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

Author: natebrix

Follow me on twitter at @natebrix.

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