What the stat's inventor did, was try to evaluate each season and assign a number (17 and above would be MVP year, 10 would be an average year). For the "weighted" rating, the player's best season is mutiplied by 100%, next best 95%, etc., down to his 19th best season being 5%). I am not really sure why, but I guess what that would tend to do is punish greatness over a long period of time and reward someone like Jim Brown who had 9 great years - note that Jim Brown is 11th on the weighted list and 21st on the non-weighted list.
The results are a bit troubling. Fran Tarkenton is a much, much better player than Jim Brown or Lawrence Taylor? Lou Groza was way, way better than Anthony Munoz? Where is Joe Montana? He did win 3 Super Bowls and ushered in an era of throwing the ball every down that we still use today......but I guess he was no Carl Eller, or for that matter Steve Young!
So there are some major flaws in the system - it doesn't seem to comport with what most people would tell you who actually watch football. (As I have pointed out before, beware of stats which result in big gaps between reality (Luis Scola ain't a great defender) and the statistical result (he is the 7th best defender in the NBA)).
But even flawed stats do provide us with lists of players who uniformly do well within those categories and who also are regarded as all-time greats by people who have watched them play. So if you take these lists and eliminate the guys who only appear on one list (Marshall Faulk, Seau, Berry, Tomlinson, Eller, Blanda), you get the following Top 22 NFL Players of all time.
22. Walter Payton (49 points, 24th on one list, 25th on the other).
21. Emmitt Smith (46)
20. Munoz (40)
19. Steve Young (39)
18. Lawrence Taylor and Alan Page (33)
16. Tom Brady and Jim Brown (32)
14. Bruce Matthews (28)
13. Derrick Brooks (27)
12. John Elway (26)
11. Rod Woodson (24)
10. Lou Groza and John Unitas (20)
8. Dan Marino (16)
Note -- there is an ENORMOUS move between 8th and 6th. Marino has 16 points, the 6th place tie has 9 points. Marino places 8th and 8th. Everyone 6th and above has an average placement of 4.5 or better.
7. Bruce Smith (13)
6. Fran Tarkenton and Reggie White (9)
4. Ray Lewis (8)
3. Brett Favre (6)
2. Peyton Manning (5)
1. Jerry Rice (4)
Now -- I presume that pro-football-reference.com does not have in Manning's 2013 season. That means when they do (it will be a 20+ season) that he will be first overall on BOTH lists and move ahead of Jerry Rice (even first and second would do it).
So, as of January 2014, the 5 greatest NFL players of all time will be:
Reggie White or Fran Tarkenton
Tom Brady will also move up higher, surpassing Jim Brown and possibly a couple others.
Here is Approximate Value (weighted) top 25 as of today:
|1.||Peyton Manning (36)||165||1998-2013||2TM|
|14.||Tom Brady (35)||139||2000-2013||nwe|
Here is the Approximate Value (not weighted) top 25 as of today.
|4.||Peyton Manning (36)||235||1998-2013||2TM|
|18.||Tom Brady (35)||177||2000-2013||nwe|