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Shutdown defenses

Posted by Doug on June 21, 2006

Last week I posted a quick entry about Champ Bailey in which I noted that Denver's opponents' top wide receivers did very well against the Broncos last year. I wondered aloud whether Bailey was as good as his reputation suggests.

That led to a lot of interesting comments, which prompted me to write a quick program to check how WR1s did against every team. If you want to see a team that really got eaten alive by top wide receivers, take a look at the Kansas City Chiefs:


WK Opposing WR1 REC YD TD
===========================================
kan 2005 1 Laveranues Coles 6 66 0
kan 2005 2 Randy Moss 5 127 1
kan 2005 3 Rod Smith 7 80 1
kan 2005 4 Terrell Owens 11 171 1
kan 2005 6 Santana Moss 10 173 2
kan 2005 7 Chris Chambers 2 88 1
kan 2005 8 Keenan McCardell 5 73 0
kan 2005 9 Randy Moss 1 7 1
kan 2005 10 Lee Evans 3 66 2
kan 2005 11 Andre Johnson 6 50 0
kan 2005 12 Deion Branch 5 49 0
kan 2005 13 Rod Smith 6 79 0
kan 2005 14 Terry Glenn 6 138 2
kan 2005 15 Plaxico Burress 2 34 0
kan 2005 16 Keenan McCardell 6 58 0
kan 2005 17 Chad Johnson 4 55 0
TOTAL 85 1314 11

A reader pointed out that top wide receivers did not do well against the Packers and indeed they did not:


WK Opposing WR1 REC YD TD
===========================================
gnb 2005 1 Roy Williams 2 13 0
gnb 2005 2 Antonio Bryant 3 32 0
gnb 2005 3 Joey Galloway 5 53 2
gnb 2005 4 Steve Smith 2 12 0
gnb 2005 5 Donte Stallworth 1 6 0
gnb 2005 7 Travis Taylor 3 36 0
gnb 2005 8 Chad Johnson 5 62 0
gnb 2005 9 Hines Ward 1 12 0
gnb 2005 10 Brian Finneran 4 50 0
gnb 2005 11 Travis Taylor 2 33 0
gnb 2005 13 Muhsin Muhammad 0 0 0
gnb 2005 14 Roy Williams 4 53 1
gnb 2005 15 Derrick Mason 5 97 0
gnb 2005 16 Muhsin Muhammad 5 58 1
gnb 2005 17 Joe Jurevicius 2 11 1
TOTAL 44 528 5

I am defining each team's top wide receiver as the guy who scored the most total fantasy points during the season. So, for example, Terrell Owens was Philadelphia's top wide receiver last year. Since he was not playing when the Eagles met the Packers in week 12, you see no entry for week 12 in the Packers' table above.

Here is a table showing every team's performance against top wide receivers last season, ordered from worst to best (fantasy points per game).


TM YR G REC YD TD
===========================
nyg 2005 | 14 73 1104 12
kan 2005 | 16 85 1314 11
nwe 2005 | 16 72 1165 13
sea 2005 | 13 75 1077 8
mia 2005 | 16 82 1144 13
sfo 2005 | 16 86 1387 7
hou 2005 | 16 80 1108 11
dal 2005 | 15 67 1141 8
stl 2005 | 15 74 1109 8
chi 2005 | 15 75 1140 8
ari 2005 | 14 79 968 9
buf 2005 | 16 86 1270 6
ten 2005 | 16 73 1003 10
nor 2005 | 15 58 846 10
phi 2005 | 16 66 998 9
den 2005 | 16 85 1250 4
min 2005 | 15 74 1023 6
car 2005 | 15 75 957 7
cin 2005 | 16 78 1079 6
cle 2005 | 13 67 869 5
ind 2005 | 15 71 968 6
sdg 2005 | 16 79 992 7
oak 2005 | 15 69 993 5
det 2005 | 16 69 982 6
atl 2005 | 16 87 1058 5
jax 2005 | 14 60 786 6
bal 2005 | 16 70 965 4
pit 2005 | 16 69 969 3
was 2005 | 14 51 720 2
gnb 2005 | 15 44 528 5
nyj 2005 | 16 54 647 3
tam 2005 | 16 53 788 1

As you can see from the lists above, some teams (like the Chiefs) faced a tougher collection of WR1s than others (like the Packers). We're going to want to adjust for that. The aggregate 2005 average points per game posted by the collection of WR1s faced by the Chiefs was 9.7. The Chiefs allowed an average of 12.5. The aggregate 2005 average points per game posted by the top recievers the Packers faced was only 8.6. The Packers allowed 5.6. Instead of comparing the raw numbers (12.5 vs. 5.6), it makes sense to compare the differences. So we'll say the Chiefs were a +2.8, meaning they were 2.8 points per game worse than expected against WR1s. The Packers were a -3.0.

This started as a discussion of Champ Bailey, but you'll notice that I have carefully avoided mentioning Champ Bailey, Al Harris, and whoever the top corner in Kansas City is. That's because I now have it on good authority from several independent and reliable sources, including footballoutsiders, who track these things carefully, that no team has its top corner covering the other team's top wide receiver all of the time or even close to all of the time. So this isn't about measuring "shutdown corners" anymore. Still, it's interesting to see if certain teams, either through scheme or personel, tend to take the top receiver away relative to the other receivers.

Which brings up another point that was mentioned in the comments of the Champ Bailey post: some teams gave up a lot of yards to WR1s, and in general, simply because their opponents passed the ball a ton. Denver, for example, performed quite well in terms of passing yards allowed per attempt, but their opponents attempted 613 passes --- the most in the league --- so of course the Broncos are going to give up some yards. The Packers, on the other hand, were the second-least-passed-upon team in the league last year, which is part of why they did not give up many yards to top wide receivers.

I've chosen to focus on the difference between the production allowed to the top wide receiver and the production allowed to the second wide receiver. This should be independent (errr, or close enough) of how many passing attempts the team allowed. A glut or a lack of passing attempts ought to affect the WR1 and WR2 equally, so the difference between the two shouldn't be polluted by that bias.

So here's the plan:


  1. Compute the production (fantasy points per game) allowed to WR1s
  2. Adjust that to take into account the quality of the WR1s faced by the team
  3. Compute the production (fantasy points per game) allowed to WR2s
  4. Adjust that to take into account the quality of the WR2s faced by the team
  5. Look at the difference between the adjusted production allowed to WR1s and the adjusted production allowed to WR2s. That should give us a ranking of the "shutdown defenses." For reasons discussed above, it will not give us a ranking of the shutdown corners.

Here are the Denver and Green Bay lines:


+====== WR1 ======+====== WR2 ======+
TM YR DIFF | G R YD TD | G R YD TD |
==========+=======+=================+=================+
den 2005 | -1.7 | 16 85 1250 4 | 16 82 928 6 |
gnb 2005 | -3.1 | 15 44 528 5 | 13 24 378 4 |

DIFF is what we're sorting by. A negative number indicates a team that did a better job (relatively) against WR1s than against WR2s. Then you see the raw numbers allowed to WR1s and WR2s. What this means: Denver's opponents' WR1s racked up a lot of yards, but so did the WR2s. Relatively speaking, their performance was 1.7 points per game better against WR1s. If Champ Bailey were in fact always covering the other team's best wide receiver this would be evidence that he's pretty good, or at least that he's good relative to Denver's other corner. But he's not, so it's evidence of, well, I don't know what it's evidence of, but it's kind of interesting. Here is the full list:


+====== WR1 ======+====== WR2 ======+
TM YR DIFF | G R YD TD | G R YD TD |
==========+=======+=================+=================+
mia 2005 | +4.0 | 16 82 1144 13 | 12 40 567 1 |
chi 2005 | +3.9 | 15 75 1140 8 | 12 30 305 0 |
kan 2005 | +3.8 | 16 85 1314 11 | 15 49 577 3 |
sea 2005 | +3.4 | 13 75 1077 8 | 13 46 473 4 |
nyg 2005 | +3.0 | 14 73 1104 12 | 15 66 886 2 |
ind 2005 | +2.7 | 15 71 968 6 | 15 41 503 1 |
ari 2005 | +2.3 | 14 79 968 9 | 13 41 449 3 |
phi 2005 | +1.7 | 16 66 998 9 | 15 51 580 3 |
dal 2005 | +1.7 | 15 67 1141 8 | 14 35 504 3 |
nor 2005 | +1.5 | 15 58 846 10 | 14 24 390 3 |
cin 2005 | +1.4 | 16 78 1079 6 | 15 46 574 2 |
det 2005 | +1.1 | 16 69 982 6 | 15 39 416 2 |
oak 2005 | +0.6 | 15 69 993 5 | 12 28 441 2 |
nwe 2005 | +0.3 | 16 72 1165 13 | 15 66 1028 3 |
atl 2005 | +0.3 | 16 87 1058 5 | 16 39 468 1 |
cle 2005 | +0.3 | 13 67 869 5 | 16 46 496 4 |
buf 2005 | +0.3 | 16 86 1270 6 | 13 47 693 2 |
car 2005 | -0.2 | 15 75 957 7 | 16 64 832 3 |
sfo 2005 | -0.3 | 16 86 1387 7 | 16 69 912 6 |
bal 2005 | -0.3 | 16 70 965 4 | 13 41 556 1 |
hou 2005 | -0.5 | 16 80 1108 11 | 14 66 992 5 |
stl 2005 | -0.8 | 15 74 1109 8 | 13 62 840 7 |
sdg 2005 | -1.4 | 16 79 992 7 | 14 61 752 3 |
den 2005 | -1.7 | 16 85 1250 4 | 16 82 928 6 |
min 2005 | -1.7 | 15 74 1023 6 | 16 55 638 6 |
pit 2005 | -1.8 | 16 69 969 3 | 14 54 764 2 |
ten 2005 | -1.9 | 16 73 1003 10 | 15 51 747 10 |
jax 2005 | -2.2 | 14 60 786 6 | 13 50 737 5 |
nyj 2005 | -3.1 | 16 54 647 3 | 16 43 527 5 |
gnb 2005 | -3.1 | 15 44 528 5 | 13 24 378 4 |
tam 2005 | -4.4 | 16 53 788 1 | 14 36 544 5 |
was 2005 | -5.7 | 14 51 720 2 | 14 61 851 6 |

This entry was posted on Wednesday, June 21st, 2006 at 4:06 am and is filed under General. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.