Every Stat Line Tells a Story

Take a look at these two running backs:

                   G   RshYd  RshTD  RecYd RecTd    FPT  

-------------------------------------------------------

Running Back A    16    1229     4     535    2     212    

Running Back B    16    1368     8     182    0     203

Just from looking at the lines of numbers, you can get a mental picture of each of these two backs. And the images you get are very different. Back A has a relatively low TD total, so maybe he gets removed at the goal line. That, together with the high receiving totals, paint a picture of a small, quick, and shifty back. Back B, on the other hand, gets it into the end zone more, but doesn't appear to be a dynamo with the hands. He has the look of a big bruiser.

Back A is Charlie Garner 1999. Back B is Eddie George 1996. Their fantasy production was very similar, but they achieved it in very different ways. You might say that they produced at similar levels, but that their production had a different shape.

Anyone who has read much of the work of baseball writer Bill James is familiar with a toy he developed called similarity scores. Essentially, the idea is to take two players' seasons and put a number on the pair that gives you an idea of how similar they are. A similarity score of 1000 means the two seasons were identical, a score of 0 would indicate two seasons that were completely and totally different. For a complete look at (a slight modification of) his system, go here.

I thought it might be fun to apply the same idea to football. So I devised the following quick formula.

  1. Start with 1000 points;
  2. Deduct half a point for each yard difference in rushing;
  3. Deduct half a point for each yard difference in receiving;
  4. Deduct 30 points for each TD difference in rushing;
  5. Deduct 30 points for each TD difference in receiving;
  6. Deduct 20 points times the difference in games played;
Let's look at a particular example:

LastName   FirstName  Year    G   RshYd  RshTD  RecYd RecTd    FPT  

------------------------------------------------------------------

Garner     Charlie    1999   16    1229     4     535    2     212    

Watters    Ricky      1999   16    1210     5     387    2     202   

  1. Start with 1000 points;
  2. Rushing yard difference = 19 yards. 19 * (1/2) = 9.5. So deduct 9.5 from the 1000, and we have 990.5;
  3. Receiving yard difference = 148 yards. 148 * (1/2) = 74. So deduct 74 from the 990.5, and we have 916.5;
  4. Deduct 30 points for the difference in rushing TDs. Now we're at 886.5;
  5. Receiving TDs were the same, so don't deduct anything there.
  6. They both played 16 games, so don't deduct anything there.
So the final similarity score ends up at 886.5. For running backs, anything over 800 indicates fairly similar seasons. In fact, I searched my database for years similar to Garner's 1999, and Watters' 1999 tops the list. You will find the top 15 later in this article.

Note that the system imposes separate penalties for differences in rushing and receiving. So if Back A had 1000 rushing yards and 600 receiving yards, and Back B had 1500 rushing yards and 100 receiving yards, the two would get a very low similarity score despite having identical total yardage. In other words, the system tries to measure not only similarity in the level of production, but also in the shape of the production.

I took six running backs and four wideouts from 1999, and found the 15 closest matches for each. I tried to select players who had rather distinctive profiles. Mostly this is just for fun, but we may learn a few things along the way.


Stephen Davis


LastName   FirstName  Year    G   RshYd  RshTD  RecYd RecTd    FPT     SIM

--------------------------------------------------------------------------

Davis      Stephen    1999   14    1405    17     111    0     254    1000

Warren     Chris      1995   16    1346    15     247    1     255     773

Allen      Terry      1996   16    1353    21     194    0     281     773

Bettis     Jerome     1996   16    1431    11     122    0     221     762

Smith      Emmitt     1999   15    1397    11     119    2     230     732

Martin     Curtis     1995   16    1487    14     261    1     265     724

Means      Natrone    1994   16    1350    12     235    0     231     721

Smith      Emmitt     1998   16    1332    13     175    2     241     712

Hampton    Rodney     1992   16    1141    14     215    0     220     686

Rhett      Errict     1995   16    1207    11     110    0     198     681

Smith      Emmitt     1994   15    1484    21     341    1     315     676

Watters    Ricky      1996   16    1411    13     444    0     264     671

Davis      Terrell    1997   15    1750    15     287    0     294     660

Stewart    James      1999   14     931    13     108    0     182     642

George     Eddie      1996   16    1368     8     182    0     203     636

Davis is at the top in bold for reference. The last column, SIM, lists the similarity score between Davis 1999 and the given player.

Note that even the most similar seasons to Davis' aren't particularly similar. Let's see what these guys looked like the next year. I threw out Stewart 99 and Emmitt 99 (because their "next year" hasn't happened yet), and I averaged the remaining 12 players. Here's the summary.


|---- Similar Year -----------|------ The Next Year --------|

 RshYd  RshTD RecYd RecTD  FPT RshYd  RshTD RecYd RecTD  FPT

 -----------------------------------------------------------

  1388    14   234     0   249  1202     9   196     1   202

On the left, under "Similar Year," you see the averages of the players who were similar to Davis. Overall, a pretty good match, but not quite perfect. The composite "similar to Davis" back had fewer rushing TDs, but more receiving, so his overall fantasy production looks about the same.

The following year, these guys lost a good bit of their value -- particularly in the form of touchdowns -- and this should not come as a surprise to anyone who read my correlation coefficient article. Still very productive the next year, but a decent drop in value. If I really wanted to do this right, I would've factored age into the similarity score, but I haven't gotten around to doing that yet.


Warrick Dunn


LastName   FirstName  Year    G   RshYd  RshTD  RecYd RecTd    FPT     SIM

--------------------------------------------------------------------------

Dunn       Warrick    1999   15     616     0     589    2     133    1000

Johnson    Anthony    1992   15     592     0     517    3     129     922

Anders     Kimble     1997   15     397     0     453    2      97     823

Murrell    Adrian     1995   15     795     1     465    2     144     819

Barber     Tiki       1999   16     258     0     609    2      99     791

Byars      Keith      1991   16     383     1     564    3     119     791

Murrell    Adrian     1999   16     553     0     335    0      89     762

Kirby      Terry      1996   14     559     3     439    1     124     757

Fletcher   Terrell    1996   16     282     0     476    2      88     757

Lee        Amp        1995   16     371     2     558    1     111     752

Bennett    Edgar      1994   16     623     5     546    4     171     745

Alstott    Mike       1996   16     377     3     557    3     129     725

Kirby      Terry      1995   16     414     4     618    3     145     715

Centers    Larry      1998   16     110     0     559    2      79     712

Byars      Keith      1992   15     176     1     502    2      86     707



|---- Similar Year -----------|------ The Next Year --------|

 RshYd  RshTD RecYd RecTD  FPT RshYd  RshTD RecYd RecTD  FPT

 -----------------------------------------------------------

   423     2   521     2   118   445     3   409     2   112

As you can see, Dunn's comps held their value fairly well. But that's easier to do if your value is low to start with.


Charlie Garner


LastName   FirstName  Year    G   RshYd  RshTD  RecYd RecTd    FPT     SIM

--------------------------------------------------------------------------

Garner     Charlie    1999   16    1229     4     535    2     212    1000

Watters    Ricky      1999   16    1210     5     387    2     202     887

Staley     Duce       1999   16    1273     4     294    2     193     858

Kaufman    Napoleon   1997   16    1294     6     403    2     218     842

Anderson   Jamal      1996   16    1055     5     473    1     189     822

Dunn       Warrick    1997   16     978     4     462    3     186     808

Staley     Duce       1998   16    1065     5     432    1     186     807

George     Eddie      1998   16    1294     5     310    1     196     795

Dillon     Corey      1999   15    1200     5     290    1     185     783

Williams   Harvey     1994   16     983     4     391    3     179     775

Heyward    Craig      1995   16    1083     6     350    2     191     775

Bennett    Edgar      1995   16    1067     3     648    4     214     773

Thomas     Thurman    1993   16    1315     6     387    0     206     763

Faulk      Marshall   1997   16    1054     7     471    1     201     761

Smith      Robert     1998   14    1187     6     291    2     196     757



|---- Similar Year -----------|------ The Next Year --------|

 RshYd  RshTD RecYd RecTD  FPT RshYd  RshTD RecYd RecTD  FPT

 -----------------------------------------------------------

  1125     5   420     2   196  1026     5   338     2   174

Note that Garner was a little bit better than most of his comps. Also note that his comps were able to come close to duplicating their numbers the following year. Again, that's to be expected of high-yardage, low-TD backs.


Dorsey Levens


LastName   FirstName  Year    G   RshYd  RshTD  RecYd RecTd    FPT     SIM

--------------------------------------------------------------------------

Levens     Dorsey     1999   14    1034     9     573    1     221    1000

Watters    Ricky      1992   14    1013     9     405    2     208     876

Faulk      Marshall   1997   16    1054     7     471    1     201     839

Davis      Terrell    1995   14    1117     7     367    1     196     796

Williams   Harvey     1995   16    1114     9     375    0     203     791

Watters    Ricky      1993   13     950    10     326    1     194     785

Hampton    Rodney     1991   14    1059    10     283    0     194     783

Anderson   Jamal      1996   16    1055     5     473    1     189     780

Faulk      Marshall   1995   16    1078    11     475    3     239     769

Parmalee   Bernie     1995   16     878     9     345    1     182     768

Watters    Ricky      1997   16    1110     7     440    0     197     766

Thomas     Thurman    1996   15    1033     8     254    0     177     760

Staley     Duce       1998   16    1065     5     432    1     186     754

Faulk      Marshall   1994   16    1282    11     522    1     252     751

Thomas     Thurman    1994   15    1093     7     349    2     198     749



|---- Similar Year -----------|------ The Next Year --------|

 RshYd  RshTD RecYd RecTD  FPT RshYd  RshTD RecYd RecTD  FPT

 -----------------------------------------------------------

  1064     8   394     1   201   940     7   364     2   180

Again, nice results. The Levens comps held their value well.


Curtis Martin


LastName   FirstName  Year    G   RshYd  RshTD  RecYd RecTd    FPT     SIM

--------------------------------------------------------------------------

Martin     Curtis     1999   16    1464     5     259    0     202    1000

Bettis     Jerome     1993   16    1429     7     244    0     209     915

George     Eddie      1998   16    1294     5     310    1     196     860

Thomas     Thurman    1993   16    1315     6     387    0     206     832

George     Eddie      1996   16    1368     8     182    0     203     824

Dillon     Corey      1999   15    1200     5     290    1     185     803

George     Eddie      1997   16    1399     6      44    1     186     800

Staley     Duce       1999   16    1273     4     294    2     193     797

Smith      Robert     1997   14    1266     6     197    1     188     770

Johnson    Anthony    1996   16    1120     6     192    0     167     765

Smith      Emmitt     1997   16    1074     4     234    0     155     763

Kaufman    Napoleon   1997   16    1294     6     403    2     218     753

Watters    Ricky      1999   16    1210     5     387    2     202     749

Warren     Chris      1994   16    1545     9     323    2     253     748

Murrell    Adrian     1996   16    1249     6      81    1     175     744



|---- Similar Year -----------|------ The Next Year --------|

 RshYd  RshTD RecYd RecTD  FPT RshYd  RshTD RecYd RecTD  FPT

 -----------------------------------------------------------

  1305     6   236     1   196  1122     7   238     1   184

Same story as many of the above. An increase in TDs offsets a decline in yardage.


Tyrone Wheatley


LastName   FirstName  Year    G   RshYd  RshTD  RecYd RecTd    FPT     SIM

--------------------------------------------------------------------------

Wheatley   Tyrone     1999   16     936     8     196    3     179    1000

Alstott    Mike       1999   16     949     7     239    2     173     912

Anderson   Jamal      1997   16    1002     7     284    3     189     893

Allen      Terry      1999   16     896     8     125    1     156     885

Murrell    Adrian     1998   15    1042     8     169    2     181     884

Alstott    Mike       1998   16     846     8     152    1     154     873

Thomas     Rodney     1995   16     947     5     204    2     157     871

Brown      Gary       1993   16    1002     6     240    2     172     855

Smith      Antowain   1997   16     840     8     177    0     150     853

Allen      Terry      1994   16    1031     8     148    0     166     839

Bates      Mario      1995   16     951     7     114    0     149     832

Rhett      Errict     1999   16     852     5     169    2     144     825

Thomas     Thurman    1995   14    1005     6     220    2     171     824

Edwards    Robert     1998   16    1115     9     331    3     217     813

Thomas     Thurman    1996   15    1033     8     254    0     177     813



|---- Similar Year -----------|------ The Next Year --------|

 RshYd  RshTD RecYd RecTD  FPT RshYd  RshTD RecYd RecTD  FPT

 -----------------------------------------------------------

   970     7   196     1   166   884     6   196     1   146

Wheatley's comps held up well also. I was expecting a bigger drop from them.


Now we take a look at some receivers. There are a few results here that surprised me.


Patrick Jeffers


LastName   FirstName  Year    G   RshYd  RshTD  RecYd RecTd    FPT     SIM

--------------------------------------------------------------------------

Jeffers    Patrick    1999   15      16     0    1082   12     182    1000

Galloway   Joey       1997   15      72     0    1049   12     184     956

Rison      Andre      1992   15       0     0    1119   11     178     944

Pickens    Carl       1994   15       0     0    1127   11     179     940

Carter     Cris       1998   16      -1     0    1011   12     173     936

Carter     Cris       1997   16       0     0    1069   13     185     936

Smith      Rod        1997   16      16     0    1180   12     192     931

Bruce      Isaac      1999   16      32     0    1165   12     192     931

Conway     Curtis     1995   16      77     0    1037   12     183     927

Pickens    Carl       1996   16       2     0    1180   12     190     924

Sharpe     Shannon    1996   15       0     0    1062   10     166     922

McCaffrey  Ed         1998   15       0     0    1053   10     165     918

Rison      Andre      1991   16      -9     0     976   12     169     915

Mathis     Terance    1998   16      -6     0    1136   11     179     912

Freeman    Antonio    1997   16      14     0    1243   12     198     899



|---- Similar Year -----------|------ The Next Year --------|

 RshYd  RshTD RecYd RecTD  FPT RshYd  RshTD RecYd RecTD  FPT

 -----------------------------------------------------------

    13     0  1096    12   180    11     0  1110    10   170

Jeffers' production was very touchdown-heavy last year, so I was expecting a significant dropoff in production by his clones. Didn't happen. Now check this one out...


Jimmy Smith


LastName   FirstName  Year    G   RshYd  RshTD  RecYd RecTd    FPT     SIM

--------------------------------------------------------------------------

Smith      Jimmy      1999   16       0     0    1636    6     200    1000

Moore      Rob        1997   16       0     0    1584    8     206     914

Irvin      Michael    1991   16       0     0    1523    8     200     884

Ellard     Henry      1994   16      -5     0    1397    6     175     878

Irvin      Michael    1995   16       0     0    1603   10     220     864

Brown      Tim        1999   16       4     0    1344    6     171     852

Thigpen    Yancey     1997   16       3     0    1398    7     182     850

Brown      Tim        1997   16      19     0    1408    5     173     847

Irvin      Michael    1992   16      -9     0    1396    7     181     846

Fryar      Irving     1997   16       0     0    1316    6     168     840

Bruce      Isaac      1996   16       4     0    1338    7     176     819

Irvin      Michael    1993   16       6     0    1330    7     176     814

Reed       Jake       1996   16       0     0    1320    7     174     812

Perriman   Brett      1995   16      48     0    1488    9     208     812

Thigpen    Yancey     1995   16       1     0    1307    5     161     805



|---- Similar Year -----------|------ The Next Year --------|

 RshYd  RshTD RecYd RecTD  FPT RshYd  RshTD RecYd RecTD  FPT

 -----------------------------------------------------------

     5     0  1416     7   185     4     0   938     5   124

This is probably just a coincidence. I repeat: this is probably just a coincidence.... but, a large number of receivers who had seasons similar to Smith's 1999 fell off a cliff the next year. In fact, if Smith's numbers decline by the same percentage as his comps did, he projects to about 1100 yards and 4 TDs. I'm not saying that's going to happen, but it's worth noting.

A couple more for you to peruse at your leisure:


Frank Sanders


LastName   FirstName  Year    G   RshYd  RshTD  RecYd RecTd    FPT     SIM

--------------------------------------------------------------------------

Sanders    Frank      1999   16       0     0     954    1     101    1000

McDuffie   O.J.       1997   16       0     0     943    1     100     995

Graham     Jeff       1999   16       0     0     968    2     109     963

Ellard     Henry      1993   16      18     0     945    2     108     957

Irvin      Michael    1998   16       1     0    1057    1     112     948

Ellard     Henry      1996   16       0     0    1014    2     113     940

Blades     Brian      1991   16      17     0    1003    2     114     937

Sanders    Frank      1995   16       1     0     883    2     100     934

Brisby     Vincent    1995   16       0     0     974    3     115     930

Morton     Johnnie    1998   16      11     0    1028    2     116     928

Chrebet    Wayne      1996   16       0     0     909    3     109     918

Slaughter  Webster    1991   16       0     0     906    3     109     916

Slaughter  Webster    1994   16       0     0     846    2      97     916

Dawkins    Sean       1998   15       0     0     823    1      88     915

Carrier    Mark       1995   16      -4     0    1002    3     118     914



|---- Similar Year -----------|------ The Next Year --------|

 RshYd  RshTD RecYd RecTD  FPT RshYd  RshTD RecYd RecTD  FPT

 -----------------------------------------------------------

     3     0   949     2   108     2     0   684     4    94


Amani Toomer


LastName   FirstName  Year    G   RshYd  RshTD  RecYd RecTd    FPT     SIM

--------------------------------------------------------------------------

Toomer     Amani      1999   16       4     0    1183    6     155    1000

Martin     Tony       1998   16       0     0    1181    6     154     997

Martin     Tony       1995   16       0     0    1224    6     158     978

Reed       Jake       1997   16       0     0    1138    6     150     976

Slaughter  Webster    1989   16       0     0    1236    6     160     972

Irvin      Michael    1994   16       0     0    1241    6     160     969

Brown      Tim        1993   16       7     0    1180    7     161     967

Coates     Ben        1994   16       0     0    1174    7     159     964

Ismail     Qadry      1999   16       4     0    1105    6     147     961

McCardell  Keenan     1997   16       0     0    1164    5     146     959

Smith      Rod        1998   16      63     0    1222    6     165     951

Freeman    Antonio    1999   16      -2     0    1074    6     143     943

Morton     Johnnie    1999   16       0     0    1129    5     143     941

Barnett    Fred       1992   16     -15     0    1083    6     143     941

Barnett    Fred       1994   16       0     0    1127    5     143     940



|---- Similar Year -----------|------ The Next Year --------|

 RshYd  RshTD RecYd RecTD  FPT RshYd  RshTD RecYd RecTD  FPT

 -----------------------------------------------------------

     5     0  1179     6   154     2     0   911     6   128