FOF Historic Files: RB Ratings

[nilodor]

So this go around I redid how I was rating players. Using data from stathead (pro-football-reference), I collected stats for all of the players. I thought some of you might be interested in how the sausage was made, so I'll start with the running backs.

A key stat I used was Approximate Value, from PFR:

Created by PFR founder Doug Drinen, the Approximate Value (AV) method is an attempt to put a single number on the seasonal value of a player at any position from any year (since 1960). The way Drinen described the intent of this measurement was:

"AV is not meant to be a be-all end-all metric. Football stat lines just do not come close to capturing all the contributions of a player the way they do in baseball and basketball. If one player is a 16 and another is a 14, we can't be very confident that the 16AV player actually had a better season than the 14AV player. But I am pretty confident that the collection of all players with 16AV played better, as an entire group, than the collection of all players with 14AV."

"Essentially, AV is a substitute for --- and a significant improvement upon, in my opinion --- metrics like 'number of seasons as a starter' or 'number of times making the pro bowl' or the like. You should think of it as being essentially like those two metrics, but with interpolation in between. That is, 'number of seasons as a starter' is a reasonable starting point if you're trying to measure, say, how good a particular draft class is, or what kind of player you can expect to get with the #13 pick in the draft. But obviously some starters are better than others. Starters on good teams are, as a group, better than starters on bad teams. Starting WRs who had lots of receiving yards are, as a group, better than starting WRs who did not have many receiving yards. Starters who made the pro bowl are, as a group, better than starters who didn't, and so on. And non-starters aren't worthless, so they get some points too."

So AV is a way to measure a players impact season to season. It's not amazing, but it is normalized by season to allow comparison between players of different eras. Now what I thought was most fair was to look at a players peak AV and 3 year Average AV. This would allow me to compare players with injury shortened careers, or careers that have just started, with long term workhorses, who rack up stats, year on year.

The top running backs by 3 Yr AV are:

Name	AV 3yr
Marshall Faulk	23.0
Jim Brown	22.0
LaDainian Tomlinson	20.7
Lydell Mitchell	20.7
Priest Holmes	20.0
Emmitt Smith	19.3
Thurman Thomas	19.3
O.J. Simpson	19.3
Terrell Davis	19.0
Tiki Barber	19.0
Edgerrin James	18.3
Leroy Kelly	17.3
Ahman Green	17.0
Barry Sanders	16.7
Walter Payton	16.7
Larry Brown	16.7
Ray Rice	15.7
Lawrence McCutcheon	15.7
Gale Sayers	15.7
Ricky Watters	15.3
Abner Haynes	15.3
Robert Smith	15.0
Garrison Hearst	15.0
Marcus Allen	15.0
Tony Dorsett	15.0
Billy Sims	15.0
Eric Dickerson	14.7
Wilbert Montgomery	14.7
Ricky Williams	14.7
Arian Foster	14.3
Shaun Alexander	14.3

Right away we have a decent list, alot of the big names are on here, with some surprises mixed in, hello Lydell Mitchell. Now AV is a all in metric, so it includes receiving and returning as well. So I set about trying to separate a players value. What I looked at was a players rushing yards per attempt, again as a 3 year average, receptions, yards per reception and fumbles.

But how to compare players of different eras? I simply normalized the stats against the season. So I have a baseline for rushing yards per attempt (Rush/Att), Receptions per Running Attempt (Rec/Rush), Receiving yards per receptions (Ryds/Rec) and fumbles

Year	Rush/Att	Rec/Rush	Ryds/Rec	Fmb/Rush+Rec
1960	4.14	0.21	11.28	0.04
1961	4.13	0.21	11.54	0.03
1962	4.14	0.21	11.56	0.03
1963	4.08	0.19	11.21	0.03
1964	3.99	0.20	10.73	0.03
1965	3.90	0.19	11.47	0.03
1966	3.88	0.19	10.61	0.02
1967	3.91	0.19	10.23	0.02
1968	3.93	0.17	9.97	0.02
1969	3.94	0.18	9.79	0.02
1970	3.72	0.18	8.71	0.03
1971	3.96	0.17	8.84	0.03
1972	4.05	0.17	9.39	0.03
1973	4.03	0.16	8.76	0.03
1974	3.83	0.18	8.41	0.03
1975	3.95	0.17	8.44	0.03
1976	4.04	0.17	8.60	0.03
1977	3.85	0.15	8.84	0.03
1978	3.97	0.17	8.50	0.03
1979	4.00	0.20	8.67	0.03
1980	3.96	0.24	8.65	0.02
1981	4.02	0.23	8.77	0.03
1982	3.84	0.23	8.66	0.03
1983	4.09	0.21	9.15	0.03
1984	4.05	0.20	8.42	0.02
1985	4.15	0.21	9.14	0.02
1986	3.93	0.23	8.82	0.02
1987	3.91	0.21	8.78	0.02
1988	3.99	0.21	9.05	0.02
1989	3.90	0.21	9.10	0.02
1990	4.05	0.20	9.02	0.02
1991	3.96	0.20	8.22	0.02
1992	4.04	0.22	8.70	0.02
1993	3.92	0.23	8.17	0.02
1994	3.75	0.24	8.07	0.02
1995	3.97	0.24	7.97	0.02
1996	3.90	0.22	8.01	0.02
1997	4.00	0.20	8.29	0.02
1998	3.97	0.20	7.87	0.01
1999	3.89	0.22	8.05	0.02
2000	4.00	0.22	8.14	0.02
2001	4.04	0.22	7.90	0.01
2002	4.15	0.23	7.75	0.01
2003	4.18	0.21	7.61	0.01
2004	4.18	0.19	7.73	0.01
2005	4.07	0.18	7.51	0.01
2006	4.19	0.20	7.71	0.01
2007	4.17	0.20	7.54	0.01
2008	4.25	0.19	7.85	0.01
2009	4.29	0.20	7.92	0.01
2010	4.18	0.20	7.87	0.01
2011	4.30	0.19	7.99	0.01
2012	4.23	0.18	7.88	0.01
2013	4.10	0.21	7.72	0.01
2014	4.13	0.21	8.15	0.01
2015	4.09	0.23	8.35	0.01
2016	4.15	0.22	8.05	0.01
2017	4.02	0.23	8.17	0.01
2018	4.35	0.25	8.05	0.01
2019	4.26	0.24	7.91	0.01
2020	4.38	0.22	7.44	0.01
2021	4.25	0.24	8.02	0.01

So now I can normalize each running backs season against their era specific stats.

Now the 3 yr peaks look like:
Rushing Yards per Attempt

Jim Brown	1.31
Barry Sanders	1.26
Marshall Faulk	1.25
O.J. Simpson	1.25
Gale Sayers	1.25
Jamaal Charles	1.24
Mercury Morris	1.23
Leroy Kelly	1.23
James Brooks	1.22
Bo Jackson	1.21
Paul Lowe	1.20
Jerious Norwood	1.19
Robert Smith	1.19
Jonathan Taylor	1.18
Nick Chubb	1.18
Earl Campbell	1.17
Napoleon Kaufman	1.17
Greg Pruitt	1.17
Stump Mitchell	1.16
Terrell Davis	1.16
DeAngelo Williams	1.16
C.J. Spiller	1.16
Tiki Barber	1.16
Felix Jones	1.16
Ronnie Harmon	1.16
J.K. Dobbins	1.15
Adrian Peterson	1.15
Delvin Williams	1.15
Emmitt Smith	1.15

So Jim Brown averaged 30% more yards per attempt than other running backs during his peak. Lydell Mitchell only averaged 2% more, ranking 442.

And we can look at the same with receptions (welcome back Lydell!)

Lydell Mitchell	3.01
Darren Sproles	2.80
Brian Westbrook	2.79
Ray Rice	2.71
Marshall Faulk	2.69
Reggie Bush	2.68
LaDainian Tomlinson	2.63
Matt Forte	2.61
Ed Podolak	2.59
Christian McCaffrey	2.57
Joe Washington	2.56
LeSean McCoy	2.56
Marcus Allen	2.54
Tiki Barber	2.53
Ronnie Harmon	2.51
Greg Pruitt	2.51
Tony Nathan	2.47
Steven Jackson	2.46
Alvin Kamara	2.46
Preston Pearson	2.44
Terry Metcalf	2.46
Priest Holmes	2.44
Amp Lee	2.44
Le'Veon Bell	2.44
Arian Foster	2.44
Pierre Thomas	2.43
Thurman Thomas	2.42
Frank Gore	2.40
Domanick Williams	2.40
Maurice Jones-Drew	2.39
Chris Johnson	2.37

Yards per reception (Lydell 424th...)

Clem Daniels	1.38
Terry Barr	1.37
Eric Metcalf	1.36
Steve Sewell	1.33
Ray Renfro	1.32
Essex Johnson	1.31
Frank Gifford	1.31
Timmy Brown	1.30
Al Carmichael	1.29
Curtis Dickey	1.29
Bruce Harper	1.29
Marshall Faulk	1.28
Donny Anderson	1.28
Jimmy Thomas	1.28
Greg Hawthorne	1.27
Billy Sims	1.27
O.J. Simpson	1.26
Lenny Moore	1.26
Preston Pearson	1.26
Ronnie Harmon	1.25
Sherman Smith	1.25
Dick James	1.24
Leroy Jackson	1.24
Calvin Hill	1.24
Larry Johnson	1.23
Larry Brown	1.23
Charley Fuller	1.23
Amp Lee	1.22
Alex Hawkins	1.22
Terry Metcalf	1.23

Combining all of these, and applying the FOF8 ratings distributions gives me the following overall ratings:

Name	Ovr Rat	Rec Rat	Fmb Rat
Marshall Faulk	9	9	9
O.J. Simpson	9	6	4
Barry Sanders	9	5	7
Jim Brown	9	2	3
Leroy Kelly	8	5	5
Tiki Barber	8	9	5
Gale Sayers	8	5	2
Walter Payton	8	6	5
Terrell Davis	8	3	5
Emmitt Smith	8	2	7
Phillip Lindsay	8	2	9
Abner Haynes	7	7	3
Priest Holmes	7	9	8
Thurman Thomas	7	8	7
Greg Pruitt	7	7	2
Earl Campbell	7	4	5
Lawrence McCutcheon	7	6	3
Robert Smith	7	4	9
Clem Daniels	6	8	2
Garrison Hearst	6	6	6
James Brooks	6	7	7
Ricky Watters	6	8	4
Adrian Peterson	6	6	6
Jamaal Charles	6	6	1
Delvin Williams	6	5	5
Tony Dorsett	6	5	2
LaDainian Tomlinson	6	6	9
Alvin Kamara	6	5	3
Ahman Green	6	5	6
Eric Dickerson	6	3	4
Chris Johnson	6	4	6
Shaun Alexander	6	3	3

I use these to give the player and draft files some personality. I'll post more positions as time allows but I thought this might interest you.

[nilodor]

In case you're heavily invested in Lydell Mitchell, he comes in with a 4/5/7

[beatle]

Very interesting. Excellent way to use data. A lot of work as well.