Posted by Doug on August 5, 2008
In yesterday's post I used a variety of metrics to determine which running back was most helped by his offensive line. All of them were lacking in one way or another, so I am going to make a more sophisticated effort with this post. Will it be a more accurate effort? I'll let you decide.
First I used my Approximate Value method to construct an aging curve for offensive linemen. This topic is itself enough for a whole post or more, but for now I'll skip it and just show you the curve.
Age PctOfPeak ============ 21 => 0.48 22 => 0.48 23 => 0.57 24 => 0.81 25 => 0.93 26 => 0.97 27 => 1.00 28 => 1.00 29 => 0.97 30 => 0.91 31 => 0.90 32 => 0.88 33 => 0.78 34 => 0.76 35 => 0.77 36 => 0.63 37 => 0.62 38 => 0.62 39 => 0.62 40 => 0.62
These numbers are fractions of peak AV. So according to this, a typical lineman has a pretty flat peak from age 26 to 29. He loses about 10% of that value by his age 30 season, and another 10ish percent by age 33. By age 40, if he's still around, he's about 60% of the player he was at his peak.
Next, I take every offensive lineman and define his Peak AV as the average of his three (not necessarily consecutive) best seasons.
Then, for each season, I multiply his peak AV by the appropriate age multiplier and assume that's about how good he was in that year.
The idea here is to get an estimate for how good a lineman was in each year of his career without making it so directly tied to the quality of his team and the honors and awards that he happened to win in just that year.
Alright, so now we've got a quality estimate for every lineman for every year. And, for all its potential faults, I do think it successfully addresses some of the concerns of the metrics we used yesterday: Anthony Munoz is distinguished from Frank Winters; non-pro-bowlers are not counted as useless; a decrepit old Bruce Matthews is not counted as equal to a prime Bruce Matthews.
Below is the same list of 100 running backs from yesterday, this time sorted by the (carry-weighted) average estimated (as above) quality of all five starting offensive linemen on each team they played for:
Jim Brown 54.99 Calvin Hill 51.96 Jim Taylor 49.74 Mark van Eeghen 49.19 Chuck Foreman 48.32 Mike Garrett 47.52 Lenny Moore 47.13 Roger Craig 46.76 Larry Csonka 45.83
Sam Cunningham 45.15 James Brooks 44.53 Terrell Davis 44.35 Robert Smith 44.09 Lydell Mitchell 43.95 Wendell Tyler 43.55 Priest Holmes 43.34 Leroy Kelly 42.92 Bill Brown 42.04 Emmitt Smith 41.83 Edgerrin James 41.62 Tony Dorsett 41.35 Lawrence McCutcheon 41.34 Earnest Byner 41.12 Thurman Thomas 40.85 Emerson Boozer 40.62 Ken Willard 40.62 Rick Casares 40.45 Delvin Williams 40.38 William Andrews 40.38 Gerald Riggs 40.27 Pete Johnson 40.25 Larry Jr. Brown 40.16 Mike Pruitt 40.09 Franco Harris 39.74 Marshall Faulk 39.44 Eric Dickerson 39.35 Eddie George 39.28 Hugh McElhenny 39.03 Freeman McNeil 39.02 Corey Dillon 38.88 Shaun Alexander 38.84 Dick Bass 38.70 Neal Anderson 38.24 Herschel Walker 37.93 John Riggins 37.77 Rudi Johnson 37.72 Ricky Watters 37.43 Ahman Green 36.86 Barry Sanders 36.80 John Henry Johnson 36.78 Marcus Allen 36.69 Clem Daniels 36.67 Jerome Bettis 36.67 Greg Pruitt 36.66 Joe Cribbs 36.64 George Rogers 36.57 Chuck Muncie 35.80 Charlie Garner 35.55 Curt Warner 35.36 Joe Morris 35.13 Wilbert Montgomery 35.12 Kevin Mack 35.11 John Brockington 35.03 Rodney Hampton 34.83 Terry Allen 34.80 Duce Staley 34.80 Clinton Portis 34.65 Fred Taylor 34.44 Curtis Martin 34.27 Don Perkins 34.18 Jim Nance 34.09 Natrone Means 33.75 Garrison Hearst 33.70 Antowain Smith 33.70 Jamal Anderson 33.68 Chris Warren 33.43 Jamal Lewis 33.26 Earl Campbell 33.03 O.J. Simpson 33.03 Ottis Anderson 32.82 Sammy Winder 32.55 James Stewart 32.26 Walter Payton 32.23 Stephen Davis 32.02 Ricky Williams 31.94 Billy Sims 31.20 Deuce McAllister 31.16 Floyd Little 31.14 Ollie Matson 30.57 Marion Butts 30.41 Tiki Barber 30.38 Thomas Jones 30.36 Mike Alstott 29.50 Warrick Dunn 29.31 Dexter Bussey 28.94 LaDainian Tomlinson 28.71 Adrian Murrell 28.40 Michael Pittman 27.54 Travis Henry 27.19 James Wilder 25.76
So what do we think of this list? I'll just make a couple of observations and then turn it over to you in the comments.
1. Emmitt Smith drops substantially compared to his placement on yesterday's lists. This method is essentially saying, "Yes, I know Emmitt played with a ton of pro bowl linemen, but c'mon, I ain't counting Mark Tuinei. Or a mid-30s Ray Donaldson or Nate Newton." Do you agree? I do.
2. Edgerrin James's appearance near the top of this list is interesting, considering he was in the bottom half of yesterday's lists. This is primarily because his Colt career coincided perfectly with the (assumed) primes of Jeff Saturday and Tarik Glenn, and the method assumes Glenn and Saturday were/are very good. James's time in Indy also featured the (assumed) peak seasons of some other solid linemen like Ryan Diem, Adam Meadows, and Rick DeMulling. [Random trivia: Edgerrin James has never played on a team with a starting lineman over age 30.]
Of course, AV only considers those guys to be solid linemen because they were multi-year starters on a great offense. This makes me suspicious that I haven't successfully eliminated the problem with using AV for this study that I mentioned yesterday.
Still, I think this is probably the best list of the four. Well, if it weren't for the fact that the process by which it was created is hopelessly complicated, I would think it was the best of the four.