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Archive for April, 2006

Red flags on Matt Leinart and Vince Young

Posted by Doug on April 28, 2006

The difference between the draft chatter you get here and the draft chatter you get everywhere else is that I admit I have no idea what I'm talking about. Still, it's Draft Eve and I can't resist sharing my impression on two of the most talked-about prospects in the draft.

I am not one of these never-ever-use-a-high-pick-on-a-quarterback guys, but I would not use a high pick on either of these two. Vince Young, in my opinion, has several small red flags, and Matt Leinart has one very big one.

First let me say that I don't have anything against either of these two. Quite the contrary; I have much appreciation for anyone that lays a beatdown on the Sooners and these two guys have certainly done that in the last two years. Aside from that, I am indifferent about Leinart. But Young I like. He's a lot of fun to watch and I hope he has a long and successful career so that I can watch a lot more of him.

Young's red flags are the ones everyone talks about: the funny release, the lack of experience in a pro-style offense, and the Wonderlic rumors. Each of these, considered individually, is not a big deal. If his only red flag was one of these, I'd take him at #1 without hesitation. But the three of them add up to a bit of concern in my mind. Were I an NFL GM, I'd certainly be a bit scared of the possibility that he'd kick my tail for the next 15 seasons with the team that picked after me, but I wouldn't take him.

Leinart, on the other hand, has no small red flags. He looks like the perfect prospect. He throws a pretty ball and does so with a scout-approved motion. He has a strong arm. He has big game experience and experience working with an NFL offensive coordinator. He even showed some impressive raw athletic ability at USC's pro day.

But I can't get past the fact that he came back for his senior season.

Please understand, I'm not saying his choice was the wrong choice for Matt Leinart the human being. I think it was a cool thing to do. If he were my son, I'd have been proud of his decision to return to USC and play another season just for fun. But if I'm considering paying him 20 million dollars to quarterback my NFL franchise, that's not an attitude I want to see. He very likely would have been the #1 pick in last year's draft. But unlike, say, Peyton Manning, he had the national championship. He had the Heisman. He had nothing to gain but fun. Gaining fun is what most 21-year-old people try to do; I understand that and I generally approve of it. But I don't think it's what Tom Brady would have done in the same situation. I don't think it's what Joe Montana would have done in the same situation. I don't think it's what Peyton Manning would have done in the same situation (yeah, you heard me, I said the same situation. I'd argue that Manning's situation was almost the exact opposite of Leinart's.).

I'll leave you with this question:

Suppose you're the Titans or the Jets or whoever, some team that's looking for a quarterback. While you're on the clock, God himself calls your war room phone and tells you that Leinart will have a career almost identical to Drew Bledsoe's. He unfortunately remains tight-lipped about everyone else. Do you take Leinart or not?

When you look at Bledsoe's career, there is a lot to like: he is currently the 7th-most prolific passer of all time by yards and 13th by touchdowns. He has won two AFC championship games (though both have asterisks). He has been to four Pro Bowls and has generally been a very solid quarterback for 13 years. But something is missing. He never has seemed --- to me anyway --- like a player you'd trade a top five draft pick for.

I unfortunately have not received any calls with inside knowledge about Matt Leinart's future. But the lack of fire/intensity/urgency/whatever revealed in Leinart's decision to return to "school" is evident in Bledsoe's personality as well. My gut tells me that Drew Bledsoe is Matt Leinart's upside.

14 Comments | Posted in NFL Draft

How quickly do Pro Bowlers become Pro Bowlers?

Posted by Doug on April 27, 2006

The differing production levels of rookies across positions led me to this question: for players that end up being good, how quickly did they get good?

To get a very quick read on this, I looked at all players whose careers started in 1970 or later and made at least one Pro Bowl in their career. For each such player, I noted the season in which he was named to his first Pro Bowl.

If you look at the 'rb' column, for example, you'll note that 23.2 percent of all running backs who eventually made a Pro Bowl made it in their rookie season, another 24.6 percent made their first Pro Bowl in their second year, and so on.


========== percentage of pro bowlers who made their ======
=========== first pro bowl in the given season ==========
POS 1 2 3 4 5 6 7 8 9 10+
================================================================
qb 1.4 23.9 12.7 14.1 9.9 4.2 12.7 4.2 5.6 11.3
rb 23.2 24.6 13.8 13.8 8.0 5.8 2.9 4.3 1.4 2.2
wr 10.8 25.0 20.0 17.5 13.3 5.8 2.5 1.7 1.7 1.7
te 10.4 20.8 16.7 14.6 10.4 6.2 14.6 2.1 2.1 2.1
ol 1.5 9.6 13.3 16.3 10.4 12.6 11.1 8.9 5.2 11.1
dl 2.1 15.0 23.6 12.1 20.0 10.7 7.1 5.0 1.4 2.9
lb 6.5 13.0 17.9 17.9 14.6 8.1 8.9 6.5 2.4 4.1
db 5.1 18.4 16.5 15.2 17.7 10.1 6.3 5.7 2.5 2.5

It is clear that the learning curves do vary quite a bit by position. For obvious reasons, rookie quarterbacks find it much more difficult to excel than rookie running backs do. Wide receivers and tight ends are somewhere in between.

The lack of rookie Pro Bowlers on the offensive line and on defense probably has as much to do with the Pro Bowl selection process as it does with the learning curve. Since there aren't as many stats to rely on, Pro Bowlers are determined more by reputation at those positions (as I discussed on this other blog before the p-f-r blog was in existence). Hence fewer young players.

6 Comments | Posted in History, NFL Draft

Rookie impact: wide receivers and tight ends

Posted by Doug on April 26, 2006

My last post was a historical look at rookie running backs. This is the same data for wide receivers:

Teams = number of teams whose leading receiver (by receptions) at the WR position was a rookie.

Elite = number of rookie wide receivers who finished in the top 10 in fantasy scoring that year.

PCT = leaguewide percentage of all wide receiver receptions that went to rookies.


Year Teams Elite PCT
=================================
1978 2 1 13.0
1979 1 0 6.3
1980 2 0 7.0
1981 2 1 6.8
1982 0 1 9.3
1983 1 0 10.0
1984 2 1 9.1
1985 3 1 15.3
1986 0 1 12.9
1987 0 0 9.6
1988 3 0 11.0
1989 2 0 11.0
1990 2 0 9.3
1991 1 0 8.5
1992 0 0 4.1
1993 1 0 8.2
1994 2 0 7.0
1995 1 0 8.9
1996 2 0 11.0
1997 2 0 4.1
1998 0 1 8.1
1999 2 0 9.8
2000 1 0 9.8
2001 1 0 9.4
2002 0 0 10.2
2003 2 1 10.9
2004 3 0 9.8
2005 0 0 7.7

And here are all teams whose top pass-catching wide receiver was a rookie:


1978
====
gnb 8- 7-1 James Lofton ( 46- 818- 6)
sdg 9- 7-0 John Jefferson ( 56-1001-13)

1979
====
nyg 6-10-0 Earnest Gray ( 28- 537- 4)

1980
====
nyj 4-12-0 Lam Jones ( 25- 482- 3)
was 6-10-0 Art Monk ( 58- 797- 3)

1981
====
chi 6-10-0 Ken Margerum ( 39- 584- 1)
cin 12- 4-0 Cris Collinsworth ( 67-1009- 8 )

1983
====
chi 8- 8-0 Willie Gault ( 40- 836- 8 )

1984
====
cle 5-11-0 Brian Brennan ( 35- 455- 3)
nyg 9- 7-0 Bobby Johnson ( 48- 795- 7)

1985
====
buf 2-14-0 Andre Reed ( 48- 637- 4)
nor 5-11-0 Eric Martin ( 35- 522- 4)
nyj 11- 5-0 Al Toon ( 46- 662- 3)

1988
====
gnb 4-12-0 Sterling Sharpe ( 55- 791- 1)
rai 7- 9-0 Tim Brown ( 43- 725- 5)
sea 9- 7-0 Brian Blades ( 40- 682- 8 )

1989
====
atl 3-13-0 Shawn Collins ( 58- 862- 3)
nwe 5-11-0 HartLee Dykes ( 49- 795- 5)

1990
====
phi 10- 6-0 Calvin Williams ( 37- 602- 9)
pho 5-11-0 Ricky Proehl ( 56- 802- 4)

1991
====
tam 3-13-0 Lawrence Dawsey ( 55- 818- 3)

1993
====
nwe 5-11-0 Vincent Brisby ( 45- 626- 2)

1994
====
cle 11- 5-0 Derrick Alexander ( 48- 828- 2)
pit 12- 4-0 Charles Johnson ( 38- 577- 3)

1995
====
nyj 3-13-0 Wayne Chrebet ( 66- 726- 4)

1996
====
ind 9- 7-0 Marvin Harrison ( 64- 836- 8 )
nwe 11- 5-0 Terry Glenn ( 90-1132- 6)

1997
====
car 7- 9-0 Rae Carruth ( 44- 545- 4)
tam 10- 6-0 Reidel Anthony ( 35- 448- 4)

1999
====
cle 2-14-0 Kevin Johnson ( 66- 986- 8 )
pit 6-10-0 Troy Edwards ( 61- 714- 5)

2000
====
cin 4-12-0 Peter Warrick ( 51- 592- 4)

2001
====
kan 6-10-0 Marvin Minnis ( 33- 511- 1)

2003
====
ari 4-12-0 Anquan Boldin (101-1377- 8 )
hou 5-11-0 Andre Johnson ( 66- 976- 4)

2004
====
ari 6-10-0 Larry Fitzgerald ( 58- 780- 8 )
det 6-10-0 Roy Williams ( 54- 817- 8 )
tam 5-11-0 Michael Clayton ( 80-1193- 7)

Despite the high (even for me) data-to-word ratio, I'm going to throw the tight end data in this post too. Note that the Teams column is a count of the number of teams whose top receiving tight end was a rookie, not the number of teams whose leading receiver was a rookie tight end. Likewise, the PCT column is the percentage of the leaguewide tight end receptions accounted for by rookies.


Year Teams Elite PCT
=================================
1978 3 1 9.3
1979 3 0 11.2
1980 6 2 16.1
1981 1 0 6.0
1982 1 0 3.7
1983 3 0 13.0
1984 1 0 5.0
1985 2 0 8.9
1986 2 0 7.7
1987 1 1 9.7
1988 4 2 12.8
1989 3 1 7.7
1990 1 1 7.7
1991 1 1 7.5
1992 0 0 6.1
1993 3 0 9.8
1994 1 0 6.4
1995 6 1 14.5
1996 3 0 7.1
1997 2 0 12.7
1998 2 1 11.7
1999 0 0 5.1
2000 3 0 8.8
2001 3 0 9.6
2002 4 2 17.6
2003 3 0 13.0
2004 2 0 10.0
2005 3 0 10.6

Teams whose top pass catching tight end was a rookie:


1978
====
cle 8- 8-0 Ozzie Newsome ( 38- 589- 2)
nyj 8- 8-0 Mickey Shuler ( 11- 67- 3)
stl 6-10-0 Eason Ramson ( 23- 238- 1)

1979
====
cin 4-12-0 Dan Ross ( 41- 516- 1)
sfo 2-14-0 Bob Bruer ( 26- 254- 1)
was 10- 6-0 Don Warren ( 26- 303- 0)

1980
====
atl 12- 4-0 Junior Miller ( 46- 584- 9)
buf 11- 5-0 Mark Brammer ( 26- 283- 4)
chi 7- 9-0 Bob Fisher ( 12- 203- 2)
min 9- 7-0 Joe Senser ( 42- 447- 7)
ram 11- 5-0 Victor Hicks ( 23- 318- 3)
stl 5-11-0 Doug Marsh ( 22- 269- 4)

1981
====
stl 7- 9-0 Greg LaFleur ( 14- 190- 2)

1982
====
sea 4- 5-0 Pete Metzelaars ( 15- 152- 0)

1983
====
buf 8- 8-0 Tony Hunter ( 36- 402- 3)
hou 2-14-0 Chris Dressel ( 32- 316- 4)
nyg 3-12-1 Zeke Mowatt ( 21- 280- 1)

1984
====
det 4-11-1 David Lewis ( 16- 236- 3)

1985
====
nyg 10- 6-0 Mark Bavaro ( 37- 511- 4)
pit 7- 9-0 Preston Gothard ( 6- 83- 0)

1986
====
den 11- 5-0 Orson Mobley ( 22- 332- 1)
nwe 11- 5-0 Greg Baty ( 37- 331- 2)

1987
====
stl 7- 8-0 Rob Awalt ( 42- 526- 6)

1988
====
chi 12- 4-0 James Thornton ( 15- 135- 0)
det 4-12-0 Pat Carter ( 13- 145- 0)
mia 6-10-0 Ferrell Edmunds ( 33- 575- 3)
phi 10- 6-0 Keith Jackson ( 81- 869- 6)

1989
====
hou 9- 7-0 Bob Mrosko ( 3- 28- 0)
rai 8- 8-0 Mike Dyal ( 27- 499- 2)
sea 7- 9-0 Robert Tyler ( 14- 148- 0)

1990
====
pit 9- 7-0 Eric Green ( 34- 387- 7)

1991
====
ram 3-13-0 Jim Price ( 35- 410- 2)

1993
====
cin 3-13-0 Tony McGee ( 44- 525- 0)
nor 8- 8-0 Irv Smith ( 16- 180- 2)
ram 5-11-0 Troy Drayton ( 27- 319- 4)

1994
====
min 10- 6-0 Andrew Jordan ( 35- 336- 0)

1995
====
ari 4-12-0 Oscar McBride ( 13- 112- 2)
det 10- 6-0 David Sloan ( 17- 184- 1)
ind 9- 7-0 Ken Dilger ( 42- 635- 4)
jax 4-12-0 Pete Mitchell ( 41- 527- 2)
pit 11- 5-0 Mark Bruener ( 26- 238- 3)
was 6-10-0 Jamie Asher ( 14- 172- 0)

1996
====
oak 7- 9-0 Rickey Dudley ( 34- 386- 4)
phi 10- 6-0 Jason Dunn ( 15- 332- 2)
ram 6-10-0 Ernie Conwell ( 15- 164- 0)

1997
====
atl 7- 9-0 O.J. Santiago ( 17- 217- 2)
sdg 4-12-0 Freddie Jones ( 41- 505- 2)

1998
====
nor 6-10-0 Cameron Cleeland ( 54- 684- 6)
was 6-10-0 Stephen Alexander ( 37- 383- 4)

2000
====
cle 3-13-0 Aaron Shea ( 30- 302- 2)
gnb 9- 7-0 Bubba Franks ( 34- 363- 1)
nyj 9- 7-0 Anthony Becht ( 16- 144- 2)

2001
====
atl 7- 9-0 Alge Crumpler ( 25- 330- 3)
nor 7- 9-0 Boo Williams ( 20- 202- 3)
sfo 12- 4-0 Eric Johnson ( 40- 362- 3)

2002
====
cin 2-14-0 Matt Schobel ( 27- 212- 2)
mia 9- 7-0 Randy McMichael ( 39- 485- 4)
nyg 10- 6-0 Jeremy Shockey ( 74- 894- 2)
oak 11- 5-0 Doug Jolley ( 32- 409- 2)

2003
====
dal 10- 6-0 Jason Witten ( 35- 347- 1)
phi 12- 4-0 L.J. Smith ( 27- 321- 1)
sdg 4-12-0 Antonio Gates ( 24- 389- 2)

2004
====
ten 5-11-0 Ben Troupe ( 33- 329- 1)
was 6-10-0 Chris Cooley ( 37- 314- 6)

2005
====
ari 5-11-0 Adam Bergen ( 28- 270- 1)
pit 11- 5-0 Heath Miller ( 39- 459- 6)
tam 11- 5-0 Alex Smith ( 41- 367- 2)

4 Comments | Posted in History, NFL Draft

Rookie impact: running backs

Posted by Doug on April 25, 2006

As the name suggests, this will be the first in a series.

In keeping with my draft week theme, I'd like to be able to present a bunch of historical draft data. But I lack draft data. That's a situation that will be changing soon, but more on that later. For now, what I can do is examine rookie data.

I decided to run a quick check to see if rookie production was increasing, decreasing, or staying level at the various skill positions. Here is the summary data for running backs. The Teams column shows how many teams had a rookie as their leading rusher (most carries). The Elite column shows how many rookie running backs were in the top 10 in fantasy points (even if you're not a fantasy player, the rankings will generally match up pretty well with "real life" rankings). The PCT column shows what percentage of all rushing attempts by running backs came from rookie running backs leagewide.


Year Teams Elite PCT
=================================
1978 2 1 10.1
1979 2 1 14.0
1980 5 3 16.6
1981 5 1 18.1
1982 2 1 12.3
1983 2 2 13.8
1984 4 0 15.2
1985 2 0 10.6
1986 3 2 18.0
1987 2 1 11.7
1988 4 1 14.5
1989 5 1 16.2
1990 2 1 15.8
1991 3 0 12.4
1992 3 1 9.2
1993 6 2 19.8
1994 3 1 16.1
1995 5 1 17.2
1996 3 2 11.6
1997 4 1 12.6
1998 3 2 13.1
1999 5 1 15.8
2000 5 1 17.9
2001 6 1 20.0
2002 4 1 15.5
2003 1 0 8.1
2004 2 0 9.2
2005 3 0 11.9

Here is a rundown of all teams that have had a rookie as their leading rusher. The data should be self-explanatory:


1978
====
buf 5-11-0 Terry Miller (238-1060- 7, 22-246-0)
hou 10- 6-0 Earl Campbell (302-1450-13, 12- 48-0)

1979
====
atl 6-10-0 William Andrews (239-1023- 3, 39-309-2)
stl 5-11-0 Ottis Anderson (331-1605- 8, 41-308-2)

1980
====
bal 7- 9-0 Curtis Dickey (176- 800-11, 25-204-2)
buf 11- 5-0 Joe Cribbs (306-1185-11, 52-415-1)
det 9- 7-0 Billy Sims (313-1303-13, 51-621-3)
nwe 10- 6-0 Vagas Ferguson (211- 818- 2, 22-173-0)
sfo 6-10-0 Earl Cooper (171- 720- 5, 83-567-4)

1981
====
kan 9- 7-0 Joe Delaney (234-1121- 3, 22-246-0)
mia 11- 4-1 Andra Franklin (201- 711- 7, 3- 6-1)
nor 4-12-0 George Rogers (378-1674-13, 16-126-0)
nwe 2-14-0 Tony Collins (204- 873- 7, 26-232-0)
nyj 10- 5-1 Freeman McNeil (137- 623- 2, 18-171-1)

1982
====
nyg 4- 5-0 Butch Woolfolk (112- 439- 2, 23-224-2)
rai 8- 1-0 Marcus Allen (160- 697-11, 38-401-3)

1983
====
ram 9- 7-0 Eric Dickerson (390-1808-18, 51-404-2)
sea 9- 7-0 Curt Warner (335-1449-13, 42-325-1)

1984
====
buf 2-14-0 Greg Bell (262-1100- 7, 34-277-1)
kan 8- 8-0 Herman Heard (165- 684- 4, 25-223-0)
min 3-13-0 Alfred Anderson (201- 773- 2, 17-102-1)
nwe 9- 7-0 Craig James (160- 790- 1, 22-159-0)

1985
====
hou 5-11-0 Mike Rozier (133- 462- 8, 9- 96-0)
sdg 8- 8-0 Tim Spencer (124- 478-10, 11-135-0)

1986
====
gnb 4-12-0 Kenneth Davis (114- 519- 0, 21-142-1)
nor 7- 9-0 Rueben Mayes (286-1353- 8, 17- 96-0)
phi 5-10-1 Keith Byars (177- 577- 1, 11- 44-0)

1987
====
kan 4-11-0 Christian Okoye (157- 660- 3, 24-169-0)
mia 8- 7-0 Troy Stradford (145- 619- 6, 48-457-1)

1988
====
buf 12- 4-0 Thurman Thomas (207- 881- 2, 18-208-0)
cin 12- 4-0 Ickey Woods (203-1066-15, 21-199-0)
nwe 9- 7-0 John Stephens (297-1168- 4, 14- 98-0)
tam 5-11-0 Lars Tate (122- 467- 7, 5- 23-1)

1989
====
den 11- 5-0 Bobby Humphrey (294-1151- 7, 22-156-1)
det 7- 9-0 Barry Sanders (280-1470-14, 24-282-0)
mia 8- 8-0 Sammie Smith (200- 659- 6, 7- 81-0)
pit 9- 7-0 Tim Worley (195- 770- 5, 15-113-0)
sdg 6-10-0 Marion Butts (170- 683- 9, 7- 21-0)

1990
====
dal 7- 9-0 Emmitt Smith (241- 937-11, 24-228-0)
pho 5-11-0 Johnny Johnson (234- 926- 5, 25-241-0)

1991
====
atl 10- 6-0 Erric Pegram (101- 349- 1, 1- -1-0)
nwe 6-10-0 Leonard Russell (266- 959- 4, 18- 81-0)
phi 10- 6-0 James Joseph (135- 440- 0, 10- 64-0)

1992
====
atl 6-10-0 Tony Smith ( 87- 329- 2, 2- 14-0)
nor 12- 4-0 Vaughn Dunbar (154- 565- 3, 9- 62-0)
sfo 14- 2-0 Ricky Watters (206-1013- 9, 43-405-2)

1993
====
ind 4-12-0 Roosevelt Potts (179- 711- 0, 26-189-0)
nor 8- 8-0 Derek Brown (180- 705- 2, 21-170-1)
pho 7- 9-0 Ronald Moore (263-1018- 9, 3- 16-0)
rai 10- 6-0 Greg Robinson (156- 591- 1, 15-142-0)
ram 5-11-0 Jerome Bettis (294-1429- 7, 26-244-0)
was 4-12-0 Reggie Brooks (223-1063- 3, 21-186-0)

1994
====
ind 8- 8-0 Marshall Faulk (314-1282-11, 52-522-1)
nor 7- 9-0 Mario Bates (151- 579- 6, 8- 62-0)
tam 6-10-0 Errict Rhett (284-1011- 7, 22-119-0)

1995
====
chi 9- 7-0 Rashaan Salaam (296-1074-10, 7- 56-0)
den 8- 8-0 Terrell Davis (237-1117- 7, 49-367-1)
hou 7- 9-0 Rodney Thomas (251- 947- 5, 39-204-2)
jax 4-12-0 James Stewart (137- 525- 2, 21-190-1)
nwe 6-10-0 Curtis Martin (368-1487-14, 30-261-1)

1996
====
hou 8- 8-0 Eddie George (335-1368- 8, 23-182-0)
mia 8- 8-0 Karim Abdul-Jabbar (307-1116-11, 23-139-0)
ram 6-10-0 Lawrence Phillips (193- 632- 4, 8- 28-1)

1997
====
buf 6-10-0 Antowain Smith (194- 840- 8, 28-177-0)
car 7- 9-0 Fred Lane (182- 809- 7, 8- 27-0)
cin 7- 9-0 Corey Dillon (233-1129-10, 27-259-0)
tam 10- 6-0 Warrick Dunn (224- 978- 4, 39-462-3)

1998
====
jax 11- 5-0 Fred Taylor (264-1223-14, 44-421-3)
nwe 9- 7-0 Robert Edwards (291-1115- 9, 35-331-3)
ram 4-12-0 Robert Holcombe ( 98- 230- 2, 6- 34-0)

1999
====
den 6-10-0 Olandis Gary (276-1159- 7, 21-159-0)
ind 13- 3-0 Edgerrin James (369-1553-13, 62-586-4)
mia 9- 7-0 J.J. Johnson (164- 558- 4, 15-100-0)
nor 3-13-0 Ricky Williams (253- 884- 2, 28-172-0)
nyg 7- 9-0 Joe Montgomery (115- 348- 3, 0- 0-0)

2000
====
bal 12- 4-0 Jamal Lewis (309-1364- 6, 27-296-0)
buf 8- 8-0 Shawn Bryson (161- 591- 0, 32-271-2)
cle 3-13-0 Travis Prentice (173- 512- 7, 37-191-1)
den 11- 5-0 Mike Anderson (297-1487-15, 23-169-0)
nyg 12- 4-0 Ron Dayne (228- 770- 5, 3- 11-0)

2001
====
buf 3-13-0 Travis Henry (213- 729- 4, 22-179-0)
chi 13- 3-0 Anthony Thomas (278-1183- 7, 22-178-0)
cle 7- 9-0 James Jackson (195- 554- 2, 7- 56-0)
ind 6-10-0 Dominic Rhodes (233-1104- 9, 34-224-0)
min 5-11-0 Michael Bennett (172- 682- 2, 29-226-1)
sdg 5-11-0 LaDainian Tomlinson (339-1236-10, 59-367-0)

2002
====
ari 5-11-0 Marcel Shipp (188- 834- 6, 38-413-3)
cle 9- 7-0 William Green (243- 887- 6, 16-113-0)
den 9- 7-0 Clinton Portis (273-1508-15, 33-364-2)
hou 4-12-0 Jonathan Wells (197- 529- 3, 9- 48-0)

2003
====
hou 5-11-0 Domanick Davis (238-1031- 8, 47-351-0)

2004
====
dal 6-10-0 Julius Jones (197- 819- 7, 17-109-0)
det 6-10-0 Kevin Jones (241-1133- 5, 28-180-1)

2005
====
gnb 4-12-0 Samkon Gado (143- 582- 6, 10- 77-1)
mia 9- 7-0 Ronnie Brown (207- 907- 4, 32-232-1)
tam 11- 5-0 Cadillac Williams (290-1178- 6, 20- 81-0)

I should note that the word "rookie" may not be technically correct in some cases. Samkon Gado, for example, was not officially a rookie last year. But I'm counting players who had no previous game experience.

6 Comments | Posted in History, NFL Draft

It’s draft week

Posted by Doug on April 24, 2006

Most football blogs have probably been in all-draft-all-the-time mode for several weeks now, and rightly so. But I believe in sticking to the things I know, or at least have an informed opinion about. And the draft is not one of those things. I will probably recognize the names of all the players drafted in the first round and most drafted in the second, and I'll be able to recite much of what the people who know are saying about them. But that's about as far as it goes.

Nonetheless, it just wouldn't be right for me to let this week pass with no draft talk at all. With that in mind, I asked my footballguys.com colleague Sigmund Bloom --- the most reasonable draft pundit I know --- if he'd be willing to put together a first round mock draft for me. Turns out he had just worked one out for posting at footballguys, but I'll post it here too.


  1. Houston - Reggie Bush, RB, USC - Maybe there's something to this Mario Williams talk. Maybe the Texans are smarting from passing on Williams when his name was Julius Peppers. I still think at the end of the day, Bush is the kind of player you can not pass on. I think they would be open to a trade, but no one has the incentive to pay the steep price to move because of the depth of the elite tier in this draft.

  2. New Orleans - D'Brickashaw Ferguson, OT, Virginia - Mario Williams may well be the #2 prospect in this draft, but to me, Ferguson makes sense to protect the Saints investment in Drew Brees. Williams would not completely shock me, but I don't buy it. A pick of a QB would be deja vu for Brees.

  3. Tennessee - Matt Leinart, QB, USC - I don't think the Titans have an incentive to move up if they really are that split between the three QBs. I wouldn't be shocked to see one of the others, but I really like the idea of the high first round QB having a coordinator that he has already flourished with. There's no ramp up, they can get to work from day one. If the Titans are serious about starting their rookie this year, it better be Leinart.

  4. NY Jets - Mario Williams, DE, NC State - It will be a real boon to Eric Mangini if this prototype falls to #4. In most drafts, he's an easy top 3 pick and possibly #1. They need a QB, but Williams arguably has even more value in Mangini's hybrid scheme because he is so well suited for multiple roles.

  5. Green Bay - A.J. Hawk, LB, Ohio State - Like New York, Green Bay should feel lucky to get a player of this caliber in a rare down year. Hawk is a can't miss prospect, the Reggie Bush of linebackers. He is a perfect tonic for the Packers defense.

  6. San Francisco - Vernon Davis, TE, Maryland - Usually you take a top WR prospect in the second year for your franchise QB. With no A+ WR to take here, the 49ers take a guy with the talent to have that kind of impact, but just at the TE position instead. I wouldn't argue with Michael Huff here, I am that high on him.

  7. Oakland - Vince Young, QB, Texas - Add Oakland to the list of big winners if Young falls to them. The freewheeling style of offense that Al Davis seems to prefer will be good for Young's playing style. No knock on Andrew Walter, but he hasn't done anything yet, and Aaron Brooks is just keeping the position warm for someone else. I don't think Young gets past them.

  8. Buffalo - Brodrick Bunkley, DT, Florida St - Justice and Huff make sense, too. Ngata has gone from the consensus pick early to a less likely pick. I think he could work in a cover 2, but Bunkley is more ideal. The need is immediate, although you could argue that it was immediate on the offensive line too. I'm really left to flip a coin between Bunkley and Justice when I ponder this pick.

  9. Detroit - Michael Huff, S, Texas - I don't see anyone on the roster than can effectively patrol the deep middle in the tampa 2. Having Huff play centerfield will allow a more aggressive mindset on D, much the same way Ed Reed and to a lesser extent, Sean Taylor operate in their defenses. Cutler could be the pick. Justice is also a possibility here.

  10. Arizona - Jay Cutler, QB, Vanderbilt - Cutler can be the kind of QB that maximizes Fitz and Boldin's value with his big arm, quick release, and ability to buy time. Justice could really firm up the line, and I wouldn't blame Arizona if they went that route.

  11. St. Louis - Jimmy Williams, DB, Virginia Tech - Huff would be ideal, but Williams is not a shabby consolation prize. He's big, fast, confident, and a huge hitter. Just the kind of presence the Rams secondary needs.

  12. Cleveland - Haloti Ngata, DT, Oregon - The Browns should be elated if they land this ideal 3-4 NT. There are some nice OLBs on the board here, but there should be some nice prospects left when the Browns pick later on the first day.

  13. Baltimore - Winston Justice, OT, USC - I think Tye Hill or Justice would both be excellent picks here. Justice can be a road grader at RT, but he has the athletic attributes of a LT (and Ogden isn't getting younger).

  14. Philadelphia - Chad Jackson, WR, Florida - Ernie Sims looks good here too. WR and OLB have been neglected early in drafts by Philadelphia. The WR corps is looking anemic, and Reggie Brown is better suited to work the shorter stuff while his partner stretches the defense. I think Jackson is just the guy to do that. White would be the shocker.

  15. Denver - Manny Lawson, DE/OLB, NC State - OK, this is my first "out there" pick. I'm projecting the Broncos to have acquired Javon Walker. Although, even if they haven't, I'm not sure Holmes would be the pick here. Lawson can work as a 4-3 end with just modest weight gain. Jason Taylor has been successful with a similar body type. He would be an instant boost to their pass rush.

  16. Miami - Tye Hill, CB, Clemson - The secondary badly needs some help. If Jason Allen has a clean bill of health, I wouldn't argue with him here. Since I'm not privy to that information, Ill project the safe pick here, the former RB who should become a shutdown corner in time. He is small, but he's a burner, a great athlete, and a tenacious player. He's one of my favorite players in this draft.

  17. Minnesota - Ernie Sims, LB, Florida St - He will be a coup for Minnesota if he lasts this long. He can be the disruptive force the Vikings need in their LB corps now that they are implementing the cover 2. I don't blame them if they trade this pick for Schaub, but Sims being there would make it harder.

  18. Dallas - Bobby Carpenter, LB, Ohio St - A pick that has made sense for a while. An OLB really seems like the perfect junction of value and need at 18 and at least one of Lawson and Carpenter should be here.

  19. San Diego - Johnathan Joseph, CB, South Carolina - Much like the Dolphins, the Chargers just need some guys who can cover in their secondary. Joseph is a burner with huge upside and like Hill, could contribute in some packages right away.

  20. Kansas City - Antonio Cromartie, CB, Florida St - KC is yet another team with problems at CB. Youboty and Marshall work just as much for me at this pick, its really a matter of taste. They're all worth a first to a team hurting for cover corners. I put Cromartie here because he's got the most upside.

  21. New England - Richard Marshall, CB, Fresno St - New England is the hardest team to get a read on. They hit with a Bulldog last year, why not go back to the well?

  22. San Francisco - DeAngelo Williams, RB, Memphis - I think the 49ers know they don't have a long term answer at RB on the roster. They saw enough of Williams at the Senior Bowl to know that he could be that guy.

  23. Tampa Bay -Santonio Holmes, WR, Ohio State - I know some people here believe Moss will be the pick. I think Holmes works for the same reasons - a speed merchant to stretch the field and be the heir to Galloway who can also improve the return game. Its hard to not put a tackle here, and I wonder if I put Holmes here because I didn't want him to fall out of the first. It could happen.

  24. Cincinnati - Jason Allen, DB, Tennessee - Allen's potential is not far off of Michael Huff's, if it is below it at all, more than enough to justify the medical risk. The Bengals need a safety to pair with Madieu Williams, Dexter Jackson is just a stopgap. Early mocks had a TE, but I'm not sure that any are worth it.

  25. NY Giants - Chad Greenway, LB, Iowa - Greenway takes a slight tumble. Ill admit to not being as high on him as most, that is probably influencing my mock subconsciously. Ryans would also be a nice pick here.

  26. Chicago - Ashton Youboty, CB, Ohio St - Vasher and Tillman are not as good as their highlights would lead you to believe. They need depth at CB as Azumah is no longer with the team. They're lucky to be looking CB in a draft deep with first round talents at the position. His hard-nosed style will fit in perfectly with the Bears.

  27. Carolina - LenDale White, RB, USC - The heir to Stephen Davis. Why not? He compliments Foster perfectly and gives them a sick two headed running attack. Foster has not made it through a full season yet and it would be foolish to assume he'll consistently do it at any point in his career. He's more valuable if he is preserved by sharing duty with a power RB. I like this marriage.

  28. Jacksonville - Demeco Ryans, LB, Alabama - Ryans is an instinctive fundamentally sound LB who Jack Del Rio should love on draft day. The Jags could also go DE here, I wouldn't argue with a pick of Kiwi or even Tamba Hali.

  29. NY Jets - Daryn Colledge, OL, Boise St - Colledge is a versatile solid offensive lineman who can play either tackle position and guard and will provide immediate depth. Maroney would work here too.

  30. Indianapolis - Laurence Maroney, RB, Minnesota - Consider Indy another big winner in the first if this junction of need, talent, and value come together. Maroney is not polished in blocking or receiving, but he's a talented runner who should feast on the defenses preoccupied by Peyton Manning.

  31. Seattle - Kelly Jennings, CB, Miami - Kelly Herndon is not a long term answer at CB. Yeah the cornerback class is talented enough to get to get seven in the first round. Its a need position for a lot of teams.

  32. Pittsburgh - D'Qwell Jackson, LB, Maryland - This is a wish pick from a fan. I know that O-line depth is the smart way to go here. Some like to put Moss here as a replacement for ARE as a returner and speedy WR. I think Jackson has the perfect makeup to play inside in the Steelers defense and has the well rounded set of skills to be an asset to a deceptive defense. He's like a QB of the defense, unbelievably football smart, and would be a huge upgrade over Larry Foote in time.

For what it's worth, Sigmund has also teamed up with Cecil Lammey and Bob Magaw to write in-depth profiles on all the quarterbacks, running backs, wide receivers, tight ends, defensive ends, defensive tackles, inside linebackers, outside linebackers, strong safeties, free safeties, and cornerbacks.

2 Comments | Posted in NFL Draft

Extra point: what’s the point?

Posted by Doug on April 21, 2006

It's Friday, so I'm going to open up the Rant category.

Just for fun some time, try the following exercise:

  1. Write a paragraph describing why you like the sport of football and/or why you like watching it.

  2. Find someone who has never seen a football game before. If you don't live abroad or work on a college campus, this could be tough, so you can just turn this into a thought experiment if necessary.

  3. Show that person video footage of an extra point being kicked and ask him to write a paragraph describing it.

I dare you to try and convince me that those two paragraphs aren't exact opposites of each other.

Despite maintaining a site with a lot of moldy old football statistics, I'm not very educated on football history. But here is the situation as I understand it. Rugby is all about running with the ball, kicking the ball, stopping people from running with or kicking the ball, and stopping people from stopping people from running with or kicking the ball. American football evolved from rugby so, in its infancy, football was about those same things.

But then football evolved. It could have evolved into a sport where kicking was even more important than in rugby. It could have evolved into a sport where the people who run with the ball must also be able to boot it. Had it done so, the resulting sport might have been just as entertaining as what we now understand as football. But it didn't. It evolved into a sport about running, passing, tackling, and blocking.

When something evolves, that doesn't necessarily imply that it is getting better in any absolute sense. It just means that it's getting better suited to a particular niche. Rugby is about speed, strength, collisions, throwing, kicking, versatility, and continuous action. Football has evolved toward the first four of those and away from the last three.

To summarize: football players used to kick the ball. Now, the players that kick the ball are not football players. Yes, yes, I understand that by definition they are football players. They wear football uniforms and get paychecks from football teams. I get that. Kicking is football in the same sense that Anna Nicole Smith is a model.

Allow me to anticipate a few objections to this post and attempt to rebut them:


  • But Doug, kickoffs and punts are some of the most exciting plays in football. I don't necessarily disagree with that, but I claim that the kick itself plays no role at all in the excitement. It's merely a means of getting to the exciting part: the return.
  • But Doug, a potential game winning field goal attempt in the last second is super duper exciting. I don't disagree that it is, but again, the kick itself is irrelevant. Any last second event that determines the outcome of the game will produce suspense, tension, and excitement. The coin flip at the beginning of overtime produces a lot of suspense, tension, and excitement. That doesn't mean that coin-flippers are football players.
  • But Doug, this is just an example of specialization. You're not opposed to specialization are you? It is true that everyone's role --- not just the kicker's --- is becoming more specialized. Offensive linemen used to carry the ball occasionally. Running backs used to have to block, throw, and run inside and outside. Running ability used to be required for quarterbacks; now it's optional. How can I be opposed to Adam Vinatieri's specialized role while not being opposed to Ted Washington's or Jerome Bettis's or Peyton Manning's? Here's how: because Bettis' role, specialized as it is, is a part of why people like football. So are Manning's and Washington's. Vinatieri's is not. That was the point of the thought experiment that started off this post.

In my hot youth, I used to be a revolutionary. Now I'm older and have less energy, so I'm content with small steps in the right direction. With that in mind, I propose the elimination of the extra point. I see a few options.


  1. A touchdown is worth 7 points

  2. A touchdown is worth 6 points and is followed by a scrimmage play from the two yard line (or wherever) that might be worth one point or two points.

I can think of a few arguments for each choice, and I'm not quite sure which I like best. That's not really the point. The point is that less kicking equals more football. And I like football.

11 Comments | Posted in Rant

Rebuilding the Favorite Toy again

Posted by Doug on April 20, 2006

Awhile back I posted a few entries (I, II, III) about estimating a player's chances at reaching a career milestone using a mathematical gadget called a Markov chain.

I figured that some baseball stathead had probably attempted something similar, so I did some googling to see if they had any luck. I did not find any Markov models, but what I did find was this interesting article at baseballthinkfactory. It was written by a guy named Jesse Frey and it's a neat idea. I'll run through the basic gist of it using --- guess who --- Clinton Portis and the rushing record as an example.

We start by collecting all 25-year-old running backs throughout NFL history (subject to some fine print). We then record how many yards they gained at age 23 and at age 24, and how many yards they gained in the rest of their careers. So we've got a list that looks something like this:


Player Age23RshYD Age24RshYD RestOfCareer
Robert Smith 632 692 4989
Ricky Ervins 680 495 939
Terrell Davis 1117 1538 4952
Barry Foster 488 1690 1562
[... another hundred-or-so guys ...]

There is, of course, no exact formula that tells you the RestOfCareer rushing yards based on the age 23 and age 24 rushing yards, but using a technique called regression we can estimate the formula that works "best."

Given the above data, what we end up with is this:


Rest-of-career yards ~= -943 + 2.64*(age24yards) + 2.39*(age23yards)

Plugging Clinton Portis' 1516 age 24 yards and 1315 age 23 yards into that formula gives an estimate of 6202 yards for the remainder of his career.

That tells us that we expect Portis to gain about 6202 more yards in the rest of his career. But of course we're not saying he'll end up with exactly that. What we're saying is that we don't know, but our best guess is that it'll be somewhere in the neighborhood of 6202. But how big is that neighborhood? Obviously there is some chance of him exceeding that by a thousand yards. There is some chance of him exceeding that by 5000 yards. How big are those chances? To answer these questions in a mathematically justifiable way is beyond the scope of this post, but we can get pretty close with the data and our intuition.

Of the 106 running backs that comprised this data set, 20 of them (about 19%) doubled the rest-of-career rushing yards estimate provided by this formula. Doubling his expected rest-of-career rushing yards is almost exactly what Portis needs to do to break Emmitt Smith's record. So this calculation indicates that Portis has about a 19% chance of retiring as the rushing king. That's pretty close to the original Favorite Toy estimate and generally agrees with my gut feeling.

Neat, huh? If I get some time, I'll run this for some other players.

4 Comments | Posted in Statgeekery

Reggie Wayne

Posted by Doug on April 19, 2006

I got an email a few days ago with the subject line: "Idea for a blog post." Because coming up with one entire idea per day can get to be a grind after awhile, sending me such an email is Step One to getting on my good side. I can use all the help I can get. But Step Two is the tricky part. That's where most people stumble, because it's a pretty sizeable leap from a subject line to an actual idea for a blog post. Most of the time the ideas are good, but often they are not feasible. Sometimes, though, they just don't make sense.

I'll let you be the judge on this one. Here is the email in full:

Man did Reggie Wayne have a down year. How does N+1 look for 27-29 year old WRs who ranked between 5-10 in N-1 and dropped at least 10 spots/out of the top 20 in year N while missing <3 games?

If that makes sense to you, you are an odd bird. If not, consider yourself lucky and allow me to translate:

Man did Reggie Wayne have a down year? If we distill his season down to its bare essentials, what we see is a young-to-prime-aged wide receiver who had an extremely good year in 2004 (he was the #8 ranked fantasy WR) and then followed it up with a disappointing 2005 (#21 ranked WR). Historically, have guys fitting that profile tended to bounce back the following year?

This will be my first post that officially gets categorized in the "Fantasy" category. While this is not a fantasy football blog, I would hope that many of the posts have some fantasy relevance anyway. Likewise, when a post is tagged as "Fantasy," I would hope that wouldn't prevent it from being interesting to non-fantasy types. The only thing you need to know is that players are ranked according to the scoring system and valuation scheme found on this page.

Let's get to the numbers. Following the emailer's suggestions, we label the good year Year N-1, the disappointing year Year N and the following year Year N+1. We require the wide receiver to be aged 27--29 in Year N+1, we require him to have finished between #5 and #10 in Year N-1, and #20 or lower in year N (while not missing more than two games). Here are all such players since 1978:


==== rank ====
Player YearN N-1 N N+1
==========================================
Eddie Brown 1989 5 25 17
Plaxico Burress 2003 8 28 43
Robert Clark 1991 10 34 127
Willie Davis 1994 9 28 47
Donald Driver 2003 10 51 10
Michael Haynes 1993 9 33 18
Tim McGee 1990 8 46 30
Stanley Morgan 1983 10 26 31
Peerless Price 2003 7 31 50
Sterling Sharpe 1991 8 21 1
John Taylor 1990 9 21 10
Hines Ward 2004 6 28 10
Steve Watson 1985 8 21 35
Reggie Wayne 2005 8 21 ??
Calvin Williams 1994 10 38 43

Aside from Wayne, there are 14 players on that list. I'll let you decide for yourself to what extent each of them truly is comparable to Reggie Wayne. Four of the fourteen returned to the top 10 the following year. Five of the fourteen ever returned to the top 10. Only Sterling Sharpe had more than one additional top 10 season in him, although the book is obviously not yet closed on Burress and Ward.

12 Comments | Posted in Fantasy

April thoughts

Posted by Doug on April 18, 2006

Some thoughts that popped into my head while perusing the footballguys news blogger.


Kevin Jones has lost some weight

I have no doubt that, like every other player in the entire NFL who played last season at a weight that was higher than what is viewed as ideal for his position, he will be Noticeably Quicker [TM]. Another interesting development is that every single player in the entire NFL who played last season at a weight lower than ideal will report to camp a few pounds heavier and therefore Better Able To Withstand The Rigors Of The Season [TM].


More on Michael Clayton

Here is a completely fabricated quote that appeared this blog awhile back:

People don’t understand the magnitude of the injuries he was playing through. We were having to drain his knee twelve times a day. The fact that he was even walking, much less giving 110% as a decoy for us, was remarkable. The doctors say they’ve never seen anyone play on a knee so messed up.

Here is an actual quote from Chris Simms:

people ... don't realize he played with a bum knee the whole year and never complained or said anything.

Not bad, eh? Let me elaborate a bit on what I said in the other post. Lots and lots and lots of players play through bum knees every year, but almost none of them disappear to the extent Clayton did. If I'm to be convinced that his historically rare collapse was solely due to the knee, then I need to be convinced that the bum knee was historically bum. I'm still not convinced.


Fred Smoot bulks up

See.


Rashaun Woods traded to San Diego

I was as high as anyone on Woods prior to the draft two years ago. In hindsight it seems that he just doesn't have the personality to be a successful NFL football player (and, in the grand scheme of things, I mean that as a compliment).

I was watching an OU-OSU basketball game from Stillwater after Woods' junior season. At halftime he was escorted to center court where he announced that he would be returning for his senior season. His demeanor was that of a shy six-year-old being forced by his parents to thank some great aunt he didn't know for some present he didn't want. The crowd, already whipped into a froth by half of an OU-OSU game, went ape. Absolutely ape. Woods smiled nervously and politely.

Obviously I don't know Woods and, even if I did, I wouldn't know enough about the relationship between personality types and NFL success to speak with any authority at all. But there seems to be something about the wide receiver position that attracts people who are the exact opposite of Rashaun Woods. Knowing what we know now, the question isn't, "why did he bust in the NFL?" it's, "how was he so successful in college?"

In case you haven't figured it out yet, I'm an Oklahoma State Cowboy fan. Here's hoping I'm wrong on this one.


Comments Off | Posted in General

More on Schaub

Posted by Doug on April 17, 2006

Last week's Matt Schaub post generated some very interesting discussion. A reader named Ben did a nice job of summarizing the pro-Schaub position:

Matt Shaub has looked better than Mike Vick in the preseason—much better....

The fact that Shaub has looked good in the preseason, filled in admirably when vick was injured, and knowing a 2nd rounder isnt good enough for him tells me the Falcons know he is the real deal too. They will trade him at the draft–I bet they get a 1st and a 4th for him. They’ve publically said that they wouldnt move him for a 1st, and were looking for a 1st and a 3rd....

this guy’s stepped up to the plate in game situations too. He is decisive, accurate, and can fire a cannon. He’s a young, natural leader. There’s a reason why atlanta wont give him up.

Now first let me make clear to everyone ---especially Ben --- that I do not disagree with anything he is saying here. He is articulating a widely held position. I don't consider myself knowledgeable enough to either agree or disagree with it. I am skeptical of it, but my general policy is to be skeptical of everything.

There is a corner of my brain that, for the purposes of this discussion, you can visualize as a tattered piece of paper on which is scrawled a list. And the title of that list is "Crazy ideas I will try if I ever own an NFL franchise." The ongoing Schaub hype has caused me to add an entry to the list.

The plan is this. Every year, draft two quarterbacks on the second day of the draft. Pick the best one and then, in the preseason, make sure that most of his game action is with my first string offense but against the opponents' second string defense. Constantly tell anyone who will listen that he is nearly as good as my starter. Teach him how to sound smart and give good interviews so that the press will like him. Then insinuate to those same members of the press that I just turned down a second round pick for him and would have to think real hard about accepting a first.

Presto. I just turned a fifth round pick into a first round pick. Do this every year, then all you have to do is sit back and wait for the Lombardis to start rolling in.

Let's just pretend for a moment that this would actually work, which is a dubious supposition I admit. What is the downside? Well, if word gets out that I'm talking to Charlie Batch or Gus Frerotte, then the game is up. So I'm stuck with this kid as my backup whether he's any good or not. And if my starter gets hurt and the kid doesn't play well, all my work is for naught. And of course, unless I get lucky I can only do this once or twice before people figure it out.

I'm only half serious with all this, of course. I'm not really interested in whether this is what the Falcons have done with Schaub. I'm interested in whether this could be what they have done with Schaub.

19 Comments | Posted in General

Matt Schaub: superstar

Posted by Doug on April 14, 2006

I have a question that can't be answered with a database query, so I'm kind of at a loss. Maybe you fine folks can help.

From this article:

The Vikings offered Atlanta one of their two second-round picks for Schaub, who many believe is ready to start for a West Coast-style offense like the Vikings'.

The Falcons are evidently holding out for a first-round pick. It seems to be a foregone conlcusion among knowledgeable football fans that Schaub is the real deal.

Question 1: How do the Vikings --- or anyone else, for that matter --- know enough about Schaub to be willing to part with a second round pick for him? He has thrown 134 passes in his two year career. His career game was a loss against the Patriots in week five of last season in which he threw for nearly 300 yards. Drew Brees and Jake Plummer shredded the Patriots' defense the week before and after that one, respectively, by the way. Not that it wasn't an impressive performance, but is that the sole reason he's so popular? Has he played particularly well in the preseason?

I guess my question is more general: how much information does one NFL franchise have about a player on another franchise who has very little meaningful game experience? And in particular: what do the Vikings know about Schaub that they didn't know prior to the draft two years ago, and how did they learn it? Why is there buzz around Schaub, but not David Greene or Andrew Walter or John Navarre or Stefan LeFors? Is an untested young quarterback simply assumed to be good if his team doesn't take active steps to acquire another backup? Can a team earn a free second or third round pick every year by simultaneously protecting and hyping the players that back up their stars?

If I sound like I'm being skeptical, I'm not. In fact, a quick top-of-the-head attempt to recall similarly hyped young backup quarterbacks turns up a lot of successes and few failures. Of course, there are lots of factors causing the top of my head to remember the successes and forget the failures. Let's try to run through them.

Question 2: in the last, say 10 or 15 years, who were the hottest young backups that moved into a starting role with a different team? And what became of them? I'll start the list.

Definite successes: Brett Favre, Mark Brunell, Matt Hasselbeck, Jake Delhomme.

Marginally successful: Scott Mitchell, Aaron Brooks.

Definite failures: Rob Johnson. Does A.J. Feeley count?

16 Comments | Posted in General

49er ineptitude

Posted by Doug on April 13, 2006

I was poking around the database earlier this week and noticed that the 49ers had virtually zero tight end production last year:


| Name | G | REC YARD AVG TD |
| Billy Bajema | 15 | 5 54 10.8 0 |
| Steve Bush | 15 | 3 21 7.0 0 |
| Patrick Estes | 6 | 0 0 0.0 0 |
| Brian Jennings | 16 | 0 0 0.0 0 |
| Terry Jones | 8 | 9 76 8.4 0 |
| Trent Smith | 5 | 3 7 2.3 0 |

It's officially mid-April now, and therefore probably time to start thinking about ratcheting up the draft chatter a notch or two around here. With that in mind, I submit that Maryland tight end / cyborg Vernon Davis might be worth thinking about when the #6 pick rolls around.

But there are lots of blogs where you can find speculation about the 49ers' tight ends of 2006. This is the only place where you can find trivia which places into historical context the ineptitude of the 49ers' tight ends of 2005 (and offhand remarks about how the tight end from Oklahoma State was much less inept than the one from Oklahoma).

Glancing at the above numbers, I would have guessed that this was the worst team tight end performance in at least 10 or 20 years (run-and-shoot teams excepted). That guess was wrong. While bad, it wasn't unprecedented. In the last 10 years, I count six teams with lower tight end receiving yardage. Four of those teams were Steelers. There have also been 10 other teams in the last 10 years with zero touchdown receptions by tight ends.

So the 49er tight ends were bad, but merely worst-in-the-league bad, not once-in-a-decade bad. They were barely any worse than the Bills' tight ends last year. But I didn't want to leave you without some decent trivia, so I uncovered the following: San Francisco only had two players catch TD passes last year. That's the first time that's happened since 1978.

4 Comments | Posted in General

Offseason winners and losers

Posted by Doug on April 12, 2006

Most of the free agency dust has settled by now. If you've lost track of who's where, check out this handy dandy player movement tracker at my other site, footballguys.com. You can sort and sift the list based on a number of different criteria to get a feel for this offseason's activity.

The tracker has a column labeled "Importance" that ranks each player on a scale of one to five. Edgerrin James is a five. Darnell Alford is a one. Brian Griese is a three. These numbers are not scientifically determined and should only be used to place players into large buckets. Nonetheless, I couldn't help running with an idea suggested by a footballguys message board poster named "Kleck."

He suggested that we add up, for each team, the total "Importance" of the players acquired minus the total Importance of the players departing. This will give us an imprecise-but-generally-somewhat-reasonable measure of which teams have improved and which teams have declined. Here is the list, sorted from most improved to most declined:


TM + - NET
HOU 32 7 +25
DET 23 12 +11
WAS 20 12 +8
CAR 19 13 +6
MIA 26 20 +6
CLE 24 19 +5
STL 20 15 +5
PHI 15 10 +5
CHI 5 0 +5
ATL 14 10 +4
TEN 15 11 +4
NYG 12 9 +3
OAK 8 6 +2
SEA 16 14 +2
NYJ 17 15 +2
DAL 22 21 +1
MIN 27 26 +1
GB 16 16 +0
BUF 17 18 -1
ARI 8 9 -1
NO 19 21 -2
TB 6 9 -3
JAX 9 12 -3
CIN 7 11 -4
PIT 5 10 -5
SF 9 15 -6
BAL 12 18 -6
KC 7 14 -7
DEN 6 16 -10
SD 6 19 -13
IND 5 18 -13
NE 8 29 -21

So according to this imprecise and unscientific accounting system (by the way, did I happen to mention that this thing was not to be taken too seriously?), the Texans figure to be the most improved team in the NFL in 2006. And that's before they add Reggie Bush. It's easy to improve, of course, when you're 2-14, but that gap over the rest of the league --- imprecise and unscientific as it may be --- is substantial.

On the other end of the list, it will be very interesting to see what happens with the Patriots this year. Weis and Crennel are gone. The Brady/Belichick duo has proven to be fallible, if only just a little. And now New England loses a ton of players in the offseason, including the clutchest kicker to ever to go 1-out-of-3 on field goal attempts in a Super Bowl. Granted, most of the players they are losing are not real difference-makers. But there will be a lot of turnover on both sides of the ball, and this should be the year we find out how strong The System is.

Patriot fans will probably point out that my method doesn't count players coming back from injury, of which every team has some but the Patriots probably have more than most. They would have a point. After years of hating New England, I finally learned to coexist with them last season. Rather than relishing their potential downfall this year, I am simply watching with detached interest.

9 Comments | Posted in General

Does it matter when your bye week is?

Posted by Doug on April 11, 2006

One more quick schedule thought:

I have often wondered whether the NFL could, either intentionally or inadvertantly, give a team an advantage by putting their bye week later in the year. Wouldn't you rather your team have a week 10 bye than a week 3 bye? Who needs a week 3 bye?

First let's just check to see if the bye week itself is an advantage. Since 1995, all teams combined have a 174-164 record in the week following a bye. That's 51.5%, which is not significantly different (in the official statistical sense) from 50%.

Now let's break that down by week:


Bye week Rec. after bye
1 1- 2
2 2- 3
3 19-18
4 21-20
5 23-20
6 27-18
7 20-23
8 23-20
9 17-16
10 12-13
11 2- 3
12 0- 3
13 1- 2
14 2- 1
15 1- 2
16 3- 0

Just to make sure that's clear, the '8' line means that teams who had a week 8 bye were a collective 23-20 in week 9.

Again, nothing to see here. If I were more ambitious I would check to see if the the teams who have historically been given early byes were, as a whole, significantly stronger or weaker than those given late byes. I would also throw out the games in which both teams were coming off a bye.

But at least at first glance, what you should take from this post is that Doug likes playing with his database and is a little bit paranoid. If the NFL is rigging the bye weeks, it is at least not being too obvious about it.

4 Comments | Posted in General

Strength of schedule

Posted by Doug on April 10, 2006

The NFL schedule was released last week. Like most people who are neither season ticket holders nor executives for FOX or CBS, I like the new flexible scheduling plan that will allow more interesting games to be shown on Sunday nights.

As has been noted elsewhere, the toughest schedules (based on last year's records) belong to the Giants and Bengals, whose 2006 opponents were a combined 139-117 in 2005. The Bears have the easiest slate; their opponents were 114-142 last year.

But as we all know, some teams that were bad in 2005 will be good in 2006 and vice versa. And some schedules that look easy right now will actually be tough and vice versa. The question is: to what extent, if any, do the Bears have an advantage over the Giants because of their schedules. Two games? One game? Half a game?

To investigate this, I went back to 1990 and recorded three bits of data about every team.


  1. their own record in Year N-1
  2. their preseason estimated strength of schedule. I.e. the combined Year N-1 records of the team's Year N opponents.
  3. their record in Year N

For the 2005 New York Jets, for example, I have


  1. .625 (their 2004 record was 10-6)
  2. .535 (the combined 2004 record of their 2005 opponents)
  3. .250 (their 2005 record ended up being 4-12)

I then labeled every team, based on their Year N-1 performance, as either Very Bad (less than 5 wins), Bad (5 or 6 wins), Mediocre (7 to 9 wins), Good (10 or 11 wins), or Very Good (12 or more wins). I also labeled each team's projected schedule as either Easy (combined opponents record under .500) or Hard (over .500).

Take a look at the Very Bad teams, for example. The Very Bad teams with a projected Easy schedule averaged 6.44 wins the next year. The Very Bad teams with a projected Hard schedule averaged 6.63 wins. The difference is not significant, and that's the point. Here is the complete breakdown:


Average Wins in Year N
Easy Sched Hard Sched
Very Bad in Year N-1 6.44 6.63
Bad in Year N-1 7.67 7.26
Mediocre in Year N-1 7.82 8.27
Good in Year N-1 8.94 8.57
Very Good in Year N-1 8.78 10.06
TOTAL 7.73 8.27

An eyeballing of this table indicates that the estimated schedule strength is essentially irrelevant and official statistical tests confirm that. [For example, a regression of Year N record on Year N-1 record and projected Year N schedule strength produces a not-even-close-to-significant coefficient for schedule strength.]

Note that I'm not saying that schedule strength isn't important. Some teams will have harder schedules than others in 2006 and it will make a difference. The point is that these strength-of-schedule estimates that are being thrown around right now seem to have no role at all in determining teams' 2006 records.

7 Comments | Posted in General, Statgeekery

Inexperience at wide receiver

Posted by Doug on April 7, 2006

From this article:

Wide receiver Reggie Brown impressed the coaching staff enough as a rookie that the team is looking at him as being its No. 1 wide receiver this season.

Brown had a respectable rookie year, catching 571 yards worth of passes. The Eagles' alternatives are Todd Pinkston (career high 798 receiving yards), Greg Lewis (561), and the newly-signed Jabar Gaffney (632).

With this crew, the Eagles become the 20th team since 1995 to enter the season without a receiver who has ever caught more than 800 yards worth of passes. Here are the others:


Team WR Prev Car High
cin 2000
Damon Griffin 112
Craig Yeast 20
Ron Dugans 0
Peter Warrick 0
Danny Farmer 0

ari 2003
Jason McAddley 362
Larry Foster 283
Kevin Kasper 180
Nathan Poole 108
Bryan Gilmore 14
Bryant Johnson 0
Anquan Boldin 0

chi 2004
David Terrell 415
Justin Gage 338
Bobby Wade 137
Bernard Berrian 0

kan 1996
Victor Bailey 545
Lake Dawson 537
Tamarick Vanover 231
Danan Hughes 103
Chris Penn 24
Sean LaChapelle 23
Joe Horn 0

bal 2002
Travis Taylor 560
Brandon Stokley 344
Randy Hymes 0
Javin Hunter 0
Ron Johnson 0

pit 1995
Charles Johnson 577
Yancey Thigpen 546
Ernie Mills 386
Andre Hastings 281
Johnnie Barnes 137

tam 1997
Horace Copeland 633
Robb Thomas 545
Karl Williams 246
Brice Hunter 0
Reidel Anthony 0

nyj 1995
Charles Wilson 652
Ryan Yarborough 42
Wayne Chrebet 0

phi 2001
James Thrash 653
Na Brown 188
Todd Pinkston 181
Dameane Douglas 79
Gari Scott 0
Freddie Mitchell 0

hou 2003
Corey Bradford 697
Jabar Gaffney 483
Andre Johnson 0
Derick Armstrong 0

cle 1999
Leslie Shepherd 712
David Dunn 509
Darrin Chiaverini 0
Kevin Johnson 0
Ronnie Powell 0
Zola Davis 0

pit 2001
Troy Edwards 714
Bobby Shaw 672
Hines Ward 672
Will Blackwell 297
Plaxico Burress 273
Lenzie Jackson 5

nyg 1999
Ike Hilliard 715
Amani Toomer 360
David Patten 226
Joe Jurevicius 146
Brian Alford 11

det 2004
Tai Streets 756
Az-zahir Hakim 734
Reggie Swinton 117
David Kircus 53
Roy Williams 0
Scott Vines 0
Eddie Drummond 0

hou 2002
Jermaine Lewis 784
Corey Bradford 637
JaJuan Dawson 281
Avion Black 90
Atnaf Harris 0
Jabar Gaffney 0

ind 1996
Sean Dawkins 784
Aaron Bailey 379
Brian Stablein 95
Marvin Harrison 0
Scott Slutzker 0
Chris Doering 0

bal 1999
Jermaine Lewis 784
Qadry Ismail 696
Billy Davis 691
Justin Armour 300
Patrick Johnson 159
Brandon Stokley 0

nyg 1997
Chris Calloway 796
Thomas Lewis 694
Kevin Alexander 88
Amani Toomer 12
Ike Hilliard 0
David Patten 0

Some of these teams didn't intend to be quite so inexperienced at the position. The 2000 Bengals, for example, also had Darnay Scott on the roster, but he missed the season with an injury.

If you're a fantasy footballer thinking this situation might be fertile ground for a young wide receiver to break out with a big season, think again. By my count, only five of these teams produced a 1000-yard receiver.

1 Comment | Posted in General, History

Michael Clayton’s decline

Posted by Doug on April 6, 2006

This generic feelgood article on the Buccaneers caught my eye for a couple of reasons. First, it talks about how beneficial it is to have stability in your personnel from year to year. I'd like to investigate that, but it might take awhile before I get around to it.

For now, I wanted to ponder the case of Michael Clayton, who had one of the best rookie seasons in NFL history and followed it up one of the biggest declines in NFL history. From the article, here is Jon Gruden's take:

"We've talked privately a lot about that," Gruden said. "He did not have the same kind of year for a lot of reasons. I think the injuries, the surgeries, all those things caught up with him. The lack of any offseason? You've got to practice, man. These guys go year-round. You see the bodies of some these guys, it's insane what these guys go through to get themselves ready to play.

"And once you sacrifice half of that, or most of that preparation -- the physical preparation, mental preparation -- it catches up with you. 'Cause the other guys are just as good physically as you are. It's a fine line. And I think Michael has learned from that."

Gruden said Clayton has had "a great offseason. He's been in there every day. He's upbeat. He's alive. He got married, OK? So I'm really excited about joining forces again with him this year."

The Institution of Marriage has no bigger fans than the guy typing this (and don't think I'm sucking up; my wife wouldn't read this blog on a dare), but if I'm a Buc fan this doesn't fill me with confidence. What I want to hear is

People don't understand the magnitude of the injuries he was playing through. We were having to drain his knee twelve times a day. The fact that he was even walking, much less giving 110% as a decoy for us, was remarkable. The doctors say they've never seen anyone play on a knee so messed up.

I probably wouldn't believe that if Gruden had said it, but it'd be more comforting than "He got married, OK?" But who knows, maybe this is just the thing. Ladies of San Francisco, please monitor this situation. If Clayton turns it around, I'm going to be introducing you to a nice young man named Rashaun Woods.

For historical perspective, here are the biggest yards-per-game declines from one year to the next since 1978 (minimum 1000 yards in year one, minimum 12 games in year two).


Good year Bad year Next year
age G YD G YD G YD
Wes Chandler 27 | 8 1032 | 16 845 | 15 708
Derrick Alexander 30 | 16 1391 | 14 470 | 8 134
Michael Clayton 23 | 16 1193 | 14 372 | ? ?
Irving Fryar 36 | 16 1316 | 16 556 | 16 254
Stacey Bailey 25 | 16 1138 | 15 364 | 6 39
Roy Green 28 | 16 1555 | 13 693 | 11 517
Johnnie Morton 31 | 16 1154 | 14 397 | 16 740
Randy Moss 27 | 16 1632 | 13 767 | 16 1005
Mark Carrier 25 | 16 1422 | 16 813 | 16 698
Muhsin Muhammad 32 | 16 1405 | 15 750 | ? ?
Rob Moore 30 | 16 1584 | 16 982 | 14 621
Joe Horn 33 | 16 1399 | 13 654 | ? ?
Jerry Rice 34 | 16 1848 | 16 1254 | 2 78
Eric Metcalf 28 | 16 1189 | 16 599 | 16 576
Carlos Carson 30 | 12 1044 | 14 711 | 13 107
Nate Burleson 24 | 16 1006 | 12 328 | ? ?
John Jefferson 25 | 16 1340 | 13 632 | 8 452
Brett Perriman 32 | 16 1021 | 13 392 | 0 0
Brian Blades 25 | 16 1063 | 16 525 | 16 1003
Qadry Ismail 32 | 16 1059 | 14 462 | 0 0
Gary Clark 26 | 12 1066 | 16 892 | 15 1229
Henry Ellard 36 | 16 1014 | 16 485 | 7 115
Drew Pearson 29 | 15 1026 | 16 568 | 16 614
Robert Brooks 28 | 15 1010 | 12 420 | 0 0
Bruce Hill 25 | 14 1040 | 16 673 | 13 641
Anthony Miller 31 | 14 1079 | 16 735 | 16 645
Brandon Stokley 29 | 16 1077 | 15 543 | ? ?
Lionel Manuel 27 | 16 1029 | 16 539 | 14 169

3 Comments | Posted in General

Joey Harrington

Posted by Doug on April 5, 2006

Since 1960, there have been 373 instances of a quarterback throwing 425 or more passes in an NFL or AFL season. According to yards-per-passing-attempt (YPA), the worst two belong to the same person: Joey Harrington. Think about all the bad teams and bad quarterbacks that have come and gone in the last 46 years. According to YPA, Joey was the worst. He was also the second worst. That's mind-boggling.

[As an aside, here is a tool I programmed that will allow you to run this kind of query on your own.]

Yeah, so I rigged the cutoff to make that work. If you relax the restriction to 300 attempts --- which would include all four of Harrington's seasons --- you have 875 QB-seasons. Harrington's efforts rank #752, #777, #865, and #870.

And yeah, YPA is not the only way to judge quarterback performance. In particular, Harrington's sack totals during his first two years were historically low, indicating that he was throwing the ball away much more often than most quarterbacks. In fact, if you compute an adjusted YPA stat that includes negative sack yards in the numerator and sacks in the denominator, Harrington's numbers look better. While still bad, they were not even the worst in the league and they certainly weren't historically bad.

It is clear at this point that Harrington is not a future star. But the open questions is, can he follow the Jake Plummer / Vinny Testaverde career path? Given the right system and supporting talent, can he be the starting quarterback on a contending team? I say yes. Well, at least I say maybe.

And if I'm Joey Harrington, I'm thinking the road to recovery starts in Cincinnati and I'm begging my agent to get me into a Bengals uniform on a one-year contract. I'm not a doctor, but I don't see any way Carson Palmer will be back playing before week 6 or so. Whoever starts for those first five weeks will benefit from a good offensive line, a solid running game, one of the best receiving groups in football, and --- possibly most important for Joey --- a lack of pressure.

1 Comment | Posted in General

Rebuilding the Favorite Toy II

Posted by Doug on April 4, 2006

Let's start by keeping this as simple as possible. Clinton Portis last year was a 24-year-old running back with 1516 rushing yards. We'll ignore those last two digits and place him in the 1500--1600 category, which we'll abbreviate '15.' Clinton Portis was a 24-15 last year.

The next step is to sift through the historical data to find out what other 24-15s have done. What percentage turned into 25-17s? What percentage turned into 25-9s? And so on. As it turns out, 100% of all 24-15s --- yep, all one of them --- turned into 25-17s. We need to widen the net a bit, and that introduces the usual problems. As we widen it, we increase the sample (which is good), but we also introduce more runners who are not truly comparable to Portis (which is bad). There is no right answer. We just play around until we get something that appears to pass the eyeball test.

Here are all the runners aged 23--25 with between 1400--1699 rushing yards, along with how they did the next year;


Runner YR YD NextYrYd
Thurman Thomas 1991 1407 1487
O.J. Simpson 1972 1251 2003
Deuce McAllister 2003 1641 1074
Terrell Davis 1996 1538 1750
LaDainian Tomlinson 2003 1645 1335
Franco Harris 1975 1246 1128
Wilbert Montgomery 1979 1512 778
Walter Payton 1979 1610 1460
Earl Campbell 1979 1697 1934
Barry Foster 1992 1690 711
Gerald Riggs 1984 1486 1719
Mark VanEeghen 1977 1273 1080
Travis Henry 2002 1438 1356
Emmitt Smith 1994 1484 1773
Otis Armstrong 1974 1407 155
George Rogers 1981 1674 535
Earl Campbell 1978 1450 1697
Barry Sanders 1991 1548 1352
Curt Warner 1986 1481 985
Rudi Johnson 2004 1454 1458
Jerome Bettis 1997 1665 1185
Stephen Davis 1999 1405 1318
Emmitt Smith 1993 1486 1484
Jerome Bettis 1996 1431 1665
LaDainian Tomlinson 2002 1683 1645

Note that, e.g., Mark van Eeghen did not fall into the 1400--1699 yard range, but if you pro-rate his season to 16 team games he did.

Which leads to the following probabilities for Portis next year:


Yardage Probability
0-- 99 0.0
100-- 199 4.0
200-- 299 0.0
300-- 399 0.0
400-- 499 0.0
500-- 599 0.0
600-- 699 0.0
700-- 799 8.0
800-- 899 0.0
900-- 999 4.0
1000--1099 12.0
1100--1199 4.0
1200--1299 4.0
1300--1399 16.0
1400--1499 16.0
1500--1599 0.0
1600--1699 12.0
1700--2200 20.0

Although it looks choppier than it ought to, this has the right general feel. It sets the over-under for Portis' rushing yards next year at about 1400. It gives him a respectable chance of breaking out for a huge year, a slim chance of a catastrophic injury, and also a chance of a minor injury or a major decline.

So we roll a die to determine how many yards Portis will have next year. Based on what he gets, we estimate his probabilities for the following year using the same technique, roll another die, and so on.

OK, here we go. According to this method, here is the probability of Portis reaching various career yardage levels.


Yardage PctChance
18000+ 0.3%
17000+ 0.6%
16000+ 1.4%
15000+ 2.9%
14000+ 5.8%
13000+ 10.8%
12000+ 19.7%
11000+ 32.3%
10000+ 48.2%
9000+ 66.0%
8000+ 81.7%
7000+ 94.1%

The original Favorite Toy said Portis was about a 3-to-1 shot to break Smith's record. This one says he's a 300-to-1 shot. This method depends heavily on real historical data. Records, by their very nature, are historically very rare accomplishments. So we shouldn't be too surprised to see that this method thinks Portis is a longshot. But I am surprised at just how much of a longshot it thinks he is.

The problem is that we're only using one year's worth of data to estimate the following year's production. Go back to that second table at the top of the page. It says that Portis has a 4% chance of gaining between 100 and 200 yards this year. I don't think that's unreasonable. What is unreasonable is projecting the rest of Portis' career under the assumption that he is a morally a 100-yard-per-year running back. If Portis gains only 150 yards in 2006, it will be because he got hurt. But the mathematical model doesn't know that. It thinks Portis is just another Heath Evans or Shaud Williams who will be out of football shortly.

So when the simulated Portis suffers a major injury, he has almost no chance of coming back. The model needs more information. [Markov chain fans will note at this point that we're up against the "memoryless" assumption of Markov chains that I glossed over in my last post.] I can think of two ways to provide this information:


  • We could take into account more than one year's worth of statistics when determining the historical probabilities. In other words, instead of calling a hypothetically injured Portis a 25-year-old back who gained 150 yards last year, we could call him a 25-year-old back who gained 150 yards last year and 1500 the year before. This would certainly allow the model to distinguish between a hypothetical injured Clinton Portis and a healthy Shaud Williams. But it drastically cuts down the pool of available comps.
  • We could measure everything in terms of yards per game instead of raw yards. Then independently assess the probability of injuries at each age. Under this scheme, our hypothetically injured Portis would be called a 25-year-old back who averaged 78 yards per game and played two games. It's just a guess at this point but I think this plan, while not without its problems, might actually yield some reasonable probabilities.

Either way, it's going to take more programming, which takes more time, which I don't think I have right now. For now we will have to file this under "crazy ideas that don't work and may or may not be salvageable." I will throw it on the to-do list and hope to attempt to salvage it sometime.

1 Comment | Posted in Statgeekery

Rebuilding the Favorite Toy with Markov chains

Posted by Doug on April 3, 2006

As promised in this post, I'm going to create a more sohpisticated way to estimate players' chances of reaching records or milestones. I'll spend this post describing the mathematics behind my method.

A Markov chain is what I'll be using and you can think of a Markov chain in terms of a random walk. Imagine you are hiking on the following collection of trails, starting at location 1:



1
. . .
. . .
. . .
. . .
. . .
2 3 4
. . . . .. .
. . . . . . .
. .. .. . .
5 6 7 8 9

Assume that, whenever you come to a fork in the road, you are equally likely to take any of the options available to you. So for example, from location 1, you have a 1/3 probability of going to 2, a 1/3 probability of going to 3, and a 1/3 probability of going to 4. If you happen to choose 3, then you now have a 1/2 probability of proceeding to 6 and a 1/2 probability of landing at 7.

There are five possible ending points for your hike, locations 5 through 9. For a given ending point, you can compute your probability of ending up there by (1) multiplying the probabilities of the choices you had to make to end up there for each path and (2) adding the product for each path. For example, your probability of landing at location 7 via location 3 is 1/3 * 1/2 = 1/6. The probability of landing at location 7 via location 4 is 1/3 * 1/3 = 1/9. So the probability of landing at location 7 would be 1/6 + 1/9, which is 5/18 or roughly 28%.

Now, there is no reason why you, the hiker at a given fork in the road, have to choose all roads with equal probability. From location 1, you might go to 2, 3, and 4 with probabilities .2, .7, and .1 repsectively. This would, of course, lead to different probabilities of landing at each of the ending points. But as long as we know the probabilities of choosing each road (and as long as one mathematical technicality --- that we'll deal with later --- is satisfied), we can multiply and add to compute the probability of landing at each of the ending points.

You can use a Markov chain to model any system that moves from state to state with known probabilities. For example...


  • A plinko board - Plinko is an old Price Is Right game where the contestant drops a game piece into a sequence of pegs. The piece ranomly bounces down through the pegs and finally lands somewhere. For a javascript demo, go here and click the plinko link. Anyway, this can be modeled as a random walk. At each level the plinko chip has some probability of going right and some probability of going left. As it works its way down the board, it makes several of these "choices" and eventually lands at one of its ending points.
  • A game of tennis - every game starts at 0-0. From there it can go to either 15-0 or 0-15, with probabilities depending on the abilities of the competitors. From 15-0, it can go to 15-15 or it can go to 30-0, and so on. Eventually it will land on either "server wins" or "returner wins."

If this were a math class, what we'd do now is talk about how to put all the various probabilities of moving from one state to another into a big matrix. Then we'd learn how to massage that matrix into various other matrices that tell us what we want to know: what is the probability of ending up in each state? How long it will take (on average) before we land there? How much time can we expect to spend in each state?

Now let's talk about Clinton Portis. In 2005 he was a 24-year-old running back with 1516 rushing yards. Next year, he might be a 25-year-old running back with 1900 rushing yards. Or he might be a 25-year-old running back with 800 rushing yards. Or he might be a 25-year-old running back with 1600 yards. Any of those numbers, as well as several others, is possible and there is a certain probability of each. Using historical data from other 24-year-old running backs with around 1500 yards might provide us with a decent starting point for those probabilities.

If Portis gets, say, 1300 rushing yards in 2006 at age 25, then based on that we can estimate his chances of getting any given number of yards in 2007 at age 26. And so on. In other words, we can view Portis as a hiker on a system of trails not unlike the one pictured above. Or we can view him as a Plinko chip and the different pegs that he hits correspond to different yardage totals.

Eventually, Portis will retire, thus landing at some ending point in his random walk, and we can compute the probability of his landing at each of them. At some of those ending points, he will be the rushing champ. At others he won't. If we add up the probabilities of all the ending points where he's the champ, we've got our estimate of Portis' chances of breaking the record.

I claimed that this was a more mathematically sophisticated way of estimating Portis' chances of breaking Smith's rushing record, but that was a lie. Yes, there is some very serious mathematics involved in working with Markov chains. But for our purposes, we don't need any of the heavy stuff. What we're doing is no different from simulating Portis' career a gazillion times and observing how frequently he breaks the record. It can be put into a Markov chain context, but that's really not necessary. In other words, I've just tricked you into learning some math. Just so it's not a total loss, I'll point out that there is a football-related application that does rely on some mathematically deep results about Markov chains. Namely, some of college football's computer ranking systems have Markov chains at their core. I'll blog on that sometime.

The next post will describe my process for converting historical data into probabilities, and then I'll get to the results.

Comments Off | Posted in Statgeekery