A starting point for your RB projections

This here article you are about to read is, to the best of my knowledge, the most mathematically rigorous look at projections ever published. That said, it probably isn't the most useful, because math can only take you so far in a task like projecting NFL running backs. And that far isn't nearly far enough. My hope is that this article, in conjunction with information you find in other, less statistically-inclined articles, will help improve your projections.

Whatever your projection system, the starting point is probably last year's stats. Whether you're doing this consciously or not, your system likely starts with last year's numbers -- or maybe a 3-year average or something like that -- and then modifies them up or down -- possibly significantly so -- based on a number of factors.

In some of my other articles, I've looked at why you might want to modify a players projections up or down for statistical reasons. For example, a couple of consequences of this article are that RBs whose value comes through the running game are slightly more reliable than RBs who accumulate more of their fantasy points through the air. Also, RBs whose value is yardage-dependent are a little more likely to hold their value than backs whose value is touchdown-dependent.

For example, consider the following three backs:

                  G   RushYD   RushTD   RecYD   RecTD
-----------------------------------------------------
Running Back A   16    1800       5        0      0
Running Back B   16     900       3      900      2
Running Back C   16     600      10      600      5
All three scored the same number of fantasy points (assuming, as I always do, that fantasy points are defined by yards/10 + 6*TDs). However, if I knew nothing else about these three backs, I'd be fairly comfortable betting that Back A will outscore Back B, who will outscore Back C the following year. Rushing is in general more stable than receiving, and yards are more stable than TDs.

In addition, we know that, as a group, players who have good fantasy seasons (as all three of our fictitious backs above did) decline a little bit the following year. Thus it's not unreasonable to expect a slight decline out of all three.

There is a way of rolling all these ideas into one simple formula. It's called multivariate linear regression. If you're a regression pro, great. If not, don't sweat it -- I won't bore you with any details.

Here's the punchline: I fed my computer 465 running back seasons (more precisely, I told one computer program to feed that data to another computer program). The data consisted of how many yards rushing and receiving, and how many TDs rushing and receiving each RB had, and how many fantasy points he scored the next year. The computer huffed and puffed for several microseconds, finally coughing up this formula:

Projected Fantasy points in Year N+1

equals

.10*RushYD_n + 3.18*RushTD_n + .082*RecYD_n + 2.79*RecTD_n + 11.3

where RushYD_n = rushing yards per 16 games in year N; 
      RecYD_n = receiving yards per 16 games in year N;
      RushTD_n = rushing TDs per 16 games in year N; 
      RushYD_n = receiving TDs per 16 games in year N.
Important technical note: all the input data was translated to a per-16-game scale, so this formula assumes all players will play 16 games every year. More on that later.

In a generally agreed-upon mathematical sense, this is the best possible formula for predicting next year's fantasy points from last year's stats. The mathematically-inclined among you can study it and see that it does indeed take into account the factors mentioned above. If you're not into that, just run the formula for our three guinea pig backs (or better yet, just sit back while I do):

                   Projected Pts the next year
-----------------------------------------------
Running Back A              207
Running Back B              190
Running Back C              166
So, knowing nothing else about them, we would expect them all to decline, but Back A to take the smallest hit, followed by Backs B and C in that order. Remember, these guys all scored 210 the year before, but just based on the shape of their production, we forecast much different levels of success for them in the following campaign.

Very interesting note: I tried including more than one seasons worth of data, but it did not improve the accuracy of the projections at all. That's not to say it isn't relevant in certain cases, but in general it's as likely to point you in the wrong direction as the right one.

Now, this is of course a tiny piece of the projection puzzle. Another factor we can get something of a numerical handle on is age. I went back and ran this formula on all 465 RBs for which I had data. I found, not surprisingly, that it tended to underestimate young RBs and overestimate old RBs. In particular, I found that it underestimated RBs under 26 by about 10%, it overestimated RBs between 26 and 30 by about 5%, and it overestimated RBs over 30 by about 10%.

Thus, a simple but effective way of improving our formula's accuracy is to simply add 10% to the projections of anyone 26 or under, take 50ff the projections of backs aged 26 to 30, and lop 100ff the projections of backs over 30.

And this, I think, is about as far as we can go with statistics alone. Think of projections obtained with this formula as the best possible projections you can get without knowing anything about football. (OK, that's not precisely true. There are more sophisticated mathematical techniques that could be applied, but I'm trying to keep things relatively simple. Please, no emails about nonlinear regression and neural nets and whatnot).

For a humorous example of how little knowledge of the actual football world this projection system would have, consider that it projects Olandis Gary to score 234 fantasy points this year. Obviously, you know better. The point is that this formula makes an excellent starting point for your projections. Then you can use things that you know about the non-statistical issues affecting particular players and teams to modify it. In Gary's case, you'd want to modify it way, way, way down, but in most instances, just a minor amount of tinkering is in order.

Without further ado, I present this formula's 2000 RB projections. Many important disclaimers follow:

                         1999     1999   2000
LastName     FirstName    Age    FPT16   PROJ
---------------------------------------------
James        Edgerrin      21     316     294
Davis        Stephen       25     290     268
Faulk        Marshall      26     315     258
Gary         Olandis       24     232     234
Levens       Dorsey        29     252     208
George       Eddie         26     254     208
Dillon       Corey         24     197     203
Staley       Duce          24     193     199
Smith        Emmitt        30     245     193
Taylor       Fred          23     188     187
Garner       Charlie       27     212     187
Martin       Curtis        26     202     185
Biakabutuka  Tim           25     184     183
Williams     Ricky         22     157     172
Enis         Curtis        23     166     170
Watters      Ricky         30     202     167
Stewart      James         28     208     166
Smith        Robert        27     160     153
Dunn         Warrick       24     141     148
Wheatley     Tyrone        27     179     147
Alstott      Mike          26     173     146
Bettis       Jerome        27     162     144
Holmes       Priest        26     146     134
Linton       Jonathan      25     128     130
Allen        Terry         31     156     125
Rhett        Errict        29     144     125
Collins      Cecil                113     123
Kirby        Terry         29     152     121
Johnson      James         25     111     116
Oxendine     Ken           24      99     108
Huntley      Richard       27     130     107
Hoard        Leroy         31     141     107
Bennett      Donnell       27     122     103
Barber       Tiki          24      99     102
Kaufman      Napoleon      26     108     101
Smith        Antowain      27     115     101
Beasley      Fred          25      98      98
Abdul-Jabbar Karim         25      80      90
Murrell      Adrian        29      89      89
Pittman      Michael       24      81      88
Lane         Fred          24      74      88
Shehee       Rashaan       24      77      87
Phillips     Lawrence      24      83      86
Hicks        Skip          25      81      85
Hanspard     Byron         23      71      84
Hill         Greg          27      84      83
Holcombe     Robert        24      81      81
Morris       Bam           27      84      79
Basnight     Michael       22      59      73
Bynum        Kenny         25      68      72
Christian    Bob           31      95      71
Pritchett    Stanley       26      88      71
Faulk        Kevin         23      65      71
Irvin        Sedrick       21      69      69
Warren       Chris         31      75      69
Centers      Larry         31      78      62
Richardson   Tony          28      59      62
Bates        Mario         26      78      60
Stephens     Tremayne      23      63      59
Mitchell     Brian         31      59      55
Fletcher     Terrell       26      52      53
Smith        Lamar         29      51      52
Anderson     Richie        28      57      50
Loville      Derek         31      50      50
Crockett     Zack          27      55      45
IMPORTANT NOTES: With that in mind, I'll run through the first 20 or so and tell you how I'd modify them (as of August 10). Your mileage may vary greatly.

  1. Edgerrin James. Projection: 294. Modifications: None, really, because nothing has changed since last season. Maybe very slightly down because of the tougher schedule.

  2. Stephen Davis. Projection: 268. Modifications: Down because I have a nagging suspicion that last season was a fluke. Down a little because of injury concerns.

  3. Marshall Faulk. Projection: 258. Modifications: None.

  4. Olandis Gary. Projection: 232. Modifications: Obviously way down because of Terrell Davis' return.

  5. Dorsey Levens. Projection: 208. Modifications: Down a little because of injury concerns. Up a little because of the new coaching staff. Overall slightly down.

  6. Eddie George. Projection: 208. Modifications: Maybe down by a tiny bit because Pickens gives the Titans yet another excuse not to give Eddie the ball in the red zone. Up because of his rock-solid pre-1999 history. Overall about the same.

  7. Corey Dillon. Projection: 203. Modifications: I have no evidence for this, but I suspect that missing a significant chunk of training camp might increase the risk of injury. Also, there is the possibility the Bengals offense won't score a point all year. I like Dillon a lot, but this projection is a little optimistic.

  8. Duce Staley. Projection: 199. Modifications: none, really. Up slightly on a wild-ass hunch.

  9. Emmitt Smith. Projection: 193. Modifications: I'm not sure what the Dallas offense will look like with Galloway on board, so that uncertainty means down just a hair. Up because of his pre-1999 track record. Overall about the same.

  10. Fred Taylor. Projection: 187. Modifications: Down because of offensive line woes. Down because of the potential for injury. Up because Stewart's no longer around. Up because he's better than he showed last year. Overall up.

  11. Charlie Garner. Projection: 187. Modifications: None.

  12. Curtis Martin. Projection: 185. Modifications: Up a little due to the consistency he's shown throughout his career. Up a little because I think he'll be more involved in the passing game with Keyshawn gone.

  13. Tim Biakabutuka. Projection: 183. Modifications: Down because of injury history.

  14. Ricky Williams. Projection: 172. Modifications: Up a little because Ditka is gone and the offense should be better in all areas. Up a little because I simply think he's better than he showed last season.

  15. Curtis Enis. Projection: 170. Modifications: Up a little because his knee should be completely healed now. I was very impressed by him in his college days. If he ever gets back to where he was then physically, he'll be a monster in my opinion.

  16. Ricky Watters. Projection: 167. Modifications: down substantially due to the presence of Shaun Alexander.

  17. James Stewart. Projection: 166. Modifications: Up because he's out of the shadow of Fred Taylor. Down because he's out of the shadow of Tony Boselli et al. Overall up.

  18. Robert Smith. Projection: 153. Modifications: Down because of injury history.

  19. Warrick Dunn. Projection: 148. Modifications: Interesting that the formula likes him better than Alstott. If anything, slightly up because of general improvement in the Bucs' offense and because of Keyshawn's blocking ability. He'll be a bargain this year. Grab him.

  20. Tyrone Wheatley. Projection: 147. Modifications: Down a smidge because I think last year may have been a bit of a fluke.

  21. Mike Alstott. Projection: 146. Modifications: Maybe up a little because he's improved every year he's been in the league, and because of general improvement in the Bucs' offense.

  22. Jerome Bettis. Projection: 144. Modifications: This one's a toughie. I'm tempted to say down because Huntley is breathing down his neck. But Huntley was there last year and Bettis did OK. I'm tempted to say down a little because Bettis is old for his age, but I can't decide if I'm serious about that or not.

Add Terrell Davis, Jamal Anderson, and the rookies to the mix, and I come up with a top 20 that looks about like this:

  1. Edgerrin James
  2. Marshall Faulk
  3. Stephen Davis
  4. Fred Taylor
  5. Eddie George
  6. Terrell Davis
  7. Duce Staley
  8. Curtis Martin
  9. Emmitt Smith
  10. Dorsey Levens
  11. Charlie Garner
  12. Curtis Enis
  13. Ricky Williams
  14. Corey Dillon
  15. James Stewart
  16. Ron Dayne
  17. Warrick Dunn
  18. Mike Alstott
  19. Jamal Anderson
  20. Robert Smith