2012 Fantasy Football Prediction Model: Retrospective

Several months ago I laid out a simple model for forecasting fantasy football performance. My post included a table ranking players by value for draft purposes. Appropriately, in our league at Nielsen I used my own model to draft (selecting Ray Rice in the first round, followed by Victor Cruz and Wes Welker). I screwed up in a later round and accidentally selected Jason Whiten instead of Matt Ryan – but other than that I strictly followed the advice of my blog: always choose the highest ranked player from positions that needed to be filled.

So how did I do? Well, I finished third out of twelve – not bad. Let’s take a retrospective look at my model to see how accurately I predicted the 2012 fantasy football season.

My previous post provides actual 2012 statistics for all positions. I scored each player and compared to my projections. Note that my projections did not include players who did not participate in the 2011 season (e.g. Jamaal Charles) or rookies (e.g. RG III), so they are not included in the analysis. If I regard the difference between actual and projected fantasy points as “error”, then I can compute R^2 to summarize fit. I computed R^2 for two projections:

• Project 2012 points as equal to 2011 points (“2011” in the table below)
• Project 2012 points by adjusting 2011 points as described in my post (“Model”)

The results are as follows:

 Pos N 2011 Model DEF 29 0.899414 0.899414 K 26 0.961511 0.961511 QB 31 0.909683 0.887465 RB 101 0.774406 0.797133 TE 78 0.81725 0.824893 WR 124 0.806109 0.810808

The overall R^2 for the model is around 0.852. I didn’t really dig into the details too much, but I think we can reasonably conclude that:

• Kickers and Defense are pretty darn stable (probably because they largely depend on the strength of the team and opposition, which does not generally massively change between seasons).
• RB performance was the hardest to predict.
• The model worked in the sense that most positions ended up with better R^2 than if I had simply used 2011 numbers.
• The exception is for the QB position, which perhaps implies that my assumptions about touchdown production do not apply to the QB position.

In the table below I compare the points per game projected by the model (Projected) with the actual number of fantasy points in 2012 (Actual) and the relative error. I highlight a row green when the relative error is less than 10%. If it is less than 25% it is yellow, and red otherwise.

 Name Pos Projected Actual Rel. Err. Drew Brees QB 20.65682 21.59875 0.043611 Aaron Rodgers QB 22.32247 21.35625 0.045243 Tom Brady QB 20.06681 21.2675 0.056456 Cam Newton QB 19.92028 20.17875 0.012809 Adrian Peterson RB 13.7407 19.0875 0.280121 Matt Ryan QB 15.70105 19.05375 0.17596 Tony Romo QB 15.42652 17.18875 0.102522 Matthew Stafford QB 18.70318 17.08 0.095034 Ben Roethlisberger QB 14.58558 17.06154 0.145119 Arian Foster RB 18.69446 16.38125 0.141211 Andy Dalton QB 12.47327 15.6725 0.20413 Marshawn Lynch RB 13.48645 15.4125 0.124967 Josh Freeman QB 14.20246 15.40625 0.078137 Michael Vick QB 21.37533 15.168 0.409239 Carson Palmer QB 20.68852 14.688 0.408532 Eli Manning QB 16.32711 14.5575 0.12156 Joe Flacco QB 12.35432 14.555 0.151198 Kevin Kolb QB 11.33343 14.12667 0.197728 Matt Schaub QB 22.60787 13.96375 0.61904 Sam Bradford QB 16.83711 13.92375 0.209236 Ray Rice RB 17.53886 13.88125 0.263493 Calvin Johnson WR 15.14139 13.775 0.099193 Brandon Marshall WR 9.919735 13.55 0.267916 Ryan Fitzpatrick QB 13.05769 13.35625 0.022354 C.J. Spiller RB 7.19662 13.26875 0.457626 Philip Rivers QB 14.7622 13.015 0.134245 Dez Bryant WR 9.147546 13.0125 0.297019 Rob Gronkowski TE 13.32919 13 0.025322 Stevan Ridley RB 3.349849 12.4625 0.731206 A.J. Green WR 9.735794 12.4375 0.217223 Demaryius Thomas WR 6.994023 12.3375 0.433109 Jay Cutler QB 20.61836 12.308 0.6752 Frank Gore RB 10.8703 12.3 0.116236 Alex Smith QB 12.57711 12.268 0.025197 LeSean McCoy RB 16.10583 12.10833 0.330144 Christian Ponder QB 14.64461 12.04375 0.215951 Jake Locker QB 9.065129 12.01273 0.245373 Chicago Bears DE 8.4375 11.875 0.289474 Matt Forte RB 14.61648 11.82667 0.235892