A VBD primer


What does VBD stand for?

VBD stands for "value based drafting."

What is VBD all about?

I'm just going to give a brief description here. If you want a more extensive explanation, check out this article by Joe Bryant, the man who popularized VBD.

For my purposes, VBD is a method of comparing the performances of players who play different positions and players who played in different eras. The basic idea is this: a player derives value by being better than the player he'd be replaced with if he dropped off the face of the earth. Suppose you had Kurt Warner on your fantasy team last year. He was obviously quite valuable to you, as he scored a lot of fantasy points. But what if he had torn his ACL on the first play of week 1? Who would you have replaced him with? Probably someone like Mark Brunell or Jake Plummer or Kerry Collins. You probably had someone like this as your backup. If not, you could probably have traded a backup or two for a QB of that quality.

Anyway, Warner's value to you last year was not the number of fantasy points he scored. It was the number of fantasy points he scored that his replacement wouldn't have. Let's assume, just for the sake of definiteness, that the replacement would have been Plummer. Plummer scored 271 fantasy points last year while Warner scored 392. Hence, our estimate of Warner's value to you was 392 - 271, or 121 points.

That's all there is to it. For every player every season, his value is defined to be his fantasy point total minus the fantasy point total of a theoretical replacement player. That last number (the fantasy point total of the theoretical replacement) is often referred to as the baseline.

What is the baseline?

I've chosen baselines of the #12 QB, the #24 RB, the #30 WR, and the #12 TE of each season. Roughly, this corresponds to the worst starter in a "typical" fantasy league composed of 12 teams and in which a starting lineup consists of one QB, two RBs, 2.5 WRs, and 1 TE (I'm not sure whether 2 or 3 WR starters is more typical, so I just split the difference).

What's the scoring system?

I keep throwing around the term "fantasy points," so I need to tell you how I'm defining that:

Fantasy points = PassYd/25 + RushYd/10 + RecYd/10 + PassTD*6 + RushTD*6 + RecTD*6 - INT*3

Why use VBD?

Two reasons.

First, it makes comparisons possible between players at different positions. Qadry Ismail scored more fantasy points than Tony Gonzalez did last season, but that doesn't mean Ismail was more valuable to your fantasy team than Gonzo was. Why not? Because you probably had someone like James Thrash or Willie Jackson or Hines Ward or Chris Chambers on your bench. If Ismail goes down, you don't have to break the bank to find a replacement who's almost as good. If Gonzo goes down, you're looking at Jay Riemersma or Ernie Conwell. In short, Gonzalez is worth more than Ismail because the difference between Gonzo and Conwell is greater than the difference between Ismail and Chambers. That is, Ismail is more replaceable and hence less valuable.

Second, VBD allows for sensible comparison between players of different eras. Especially for the passing game, the 70s were a very different time than the 90s. In 1974, for instance, Cliff Branch had 1092 receiving yards and 13 TDs. That seems like a pretty good year, but nothing too exciting. But now consider that Branch was easily the #1 WR in the NFL that year. The #2 man, Isaac Curtis, managed only 633 receiving yards and 10 TDs. The #30 WR was Jim Lash, who compiled a measly 631 yards and zero(!) TDs. Put in this context, Branch's 1974 season has more value than, say, Marvin Harrison's 2001 season, even though Harrison had a lot more yards and TDs. In short, Harrison was more easily replaceable in 2001 than Branch was in 1974. Similarly, Bert Jones' 3100 yards and 24 TDs in 1976 was a more valuable season than Scott Mitchell's 1995 (4300 yards, 32 TDs).

Anything else I should know?

Not unless you're a real stickler for detail. If you are, then you should note that all seasons prior to 1978, when 14-game seasons were the norm, are multiplied by 16/14 to put them on equal footing with today's 16-gamers. The strike seasons of 1982 and 1987 have been adjusted similarly.

What was the best season of all-time?

My data is only complete back to 1970, so I can't tell you how Jim Brown's or Sammy Baugh's best seasons measure up, but here are the top 100 seasons since 1970:


                                  Passing    Rushing   Receiving
     Name                 Year     Yd  TD     Yd  TD     Yd  TD   VBD
-------------------------------+----------+----------+----------+-----
  1. O.J. Simpson         1975 |    0   0 | 1817  16 |  426   7 | 282
  2. Dan Marino           1984 | 5084  48 |   -7   0 |    0   0 | 243
  3. Terrell Davis        1998 |    0   0 | 2008  21 |  217   2 | 233
  4. Emmitt Smith         1995 |    0   0 | 1773  25 |  375   0 | 225
  5. Chuck Foreman        1975 |    0   0 | 1070  13 |  691   9 | 220
  6. Walter Payton        1977 |    0   0 | 1852  14 |  269   2 | 218
  7. Jerry Rice           1987 |    0   0 |   51   1 | 1078  22 | 216
  8. Marshall Faulk       2000 |    0   0 | 1359  18 |  830   8 | 216
  9. Dan Marino           1986 | 4746  44 |   -3   0 |    0   0 | 210
 10. Emmitt Smith         1992 |    0   0 | 1713  18 |  335   1 | 209
 11. Steve Young          1994 | 3969  35 |  293   7 |    0   0 | 208
 12. Marshall Faulk       2001 |    0   0 | 1382  12 |  765   9 | 206
 13. Marcus Allen         1982 |    0   0 |  697  11 |  401   3 | 203
 14. Steve Young          1998 | 4170  36 |  454   6 |    0   0 | 200
 15. Randall Cunningham   1990 | 3466  30 |  942   5 |    0   0 | 199
 16. Brett Favre          1996 | 3899  39 |  136   2 |    0   0 | 197
 17. Eric Dickerson       1983 |    0   0 | 1808  18 |  404   2 | 191
 18. Wes Chandler         1982 |    0   0 |   32   0 | 1032   9 | 190
 19. Barry Sanders        1997 |    0   0 | 2053  11 |  305   3 | 188
 20. Emmitt Smith         1994 |    0   0 | 1484  21 |  341   1 | 187
 21. Edgerrin James       1999 |    0   0 | 1553  13 |  586   4 | 186
 22. Jamal Anderson       1998 |    0   0 | 1846  14 |  319   2 | 185
 23. Marshall Faulk       1999 |    0   0 | 1381   7 | 1048   5 | 185
 24. James Wilder         1984 |   16   1 | 1544  13 |  685   0 | 182
 25. Eric Dickerson       1984 |    0   0 | 2105  14 |  139   0 | 180
 26. Kurt Warner          1999 | 4353  41 |   92   1 |    0   0 | 179
 27. Edgerrin James       2000 |    0   0 | 1709  13 |  594   5 | 179
 28. O.J. Simpson         1973 |    0   0 | 2003  12 |   70   0 | 177
 29. Marcus Allen         1984 |    0   0 | 1168  13 |  758   5 | 175
 30. Warren Moon          1990 | 4689  33 |  215   2 |    0   0 | 175
 31. Brett Favre          1995 | 4413  38 |  181   3 |    0   0 | 174
 32. Thurman Thomas       1992 |    0   0 | 1487   9 |  626   3 | 174
 33. Dalton Hilliard      1989 |   35   1 | 1262  13 |  514   5 | 173
 34. Daunte Culpepper     2000 | 3937  33 |  470   7 |    0   0 | 171
 35. Otis Armstrong       1974 |    0   0 | 1407   9 |  405   3 | 170
 36. Lydell Mitchell      1975 |    0   0 | 1193  11 |  544   4 | 169
 37. Barry Sanders        1991 |    0   0 | 1548  16 |  307   1 | 169
 38. Jeff Garcia          2000 | 4278  31 |  415   4 |    0   0 | 167
 39. Steve Young          1992 | 3465  25 |  537   4 |    0   0 | 166
 40. Marcus Allen         1985 |    0   0 | 1759  11 |  555   3 | 165
 41. Jerry Rice           1995 |    0   0 |   36   1 | 1848  15 | 165
 42. Wendell Tyler        1982 |    0   0 |  564   9 |  375   4 | 164
 43. Terrell Davis        1997 |    0   0 | 1750  15 |  287   0 | 162
 44. Billy Sims           1980 |    0   0 | 1303  13 |  621   3 | 161
 45. Joe Montana          1987 | 3054  31 |  141   1 |    0   0 | 161
 46. Barry Foster         1992 |    0   0 | 1690  11 |  344   0 | 160
 47. Vinny Testaverde     1996 | 4177  33 |  188   2 |    0   0 | 160
 48. Jerry Rice           1986 |    0   0 |   72   1 | 1570  15 | 158
 49. Thurman Thomas       1991 |    0   0 | 1407   7 |  631   5 | 157
 50. Steve Beuerlein      1999 | 4436  36 |  124   2 |    0   0 | 156
 51. Marshall Faulk       1998 |    0   0 | 1319   6 |  908   4 | 155
 52. Terry Allen          1996 |    0   0 | 1353  21 |  194   0 | 155
 53. Eric Dickerson       1988 |    0   0 | 1659  14 |  377   1 | 154
 54. Steve Young          1993 | 4023  29 |  407   2 |    0   0 | 153
 55. Chuck Foreman        1976 |    0   0 | 1155  13 |  567   1 | 152
 56. Randall Cunningham   1987 | 2786  23 |  505   3 |    0   0 | 151
 57. Bert Jones           1976 | 3104  24 |  214   2 |    0   0 | 151
 58. Barry Sanders        1990 |    0   0 | 1304  13 |  480   3 | 150
 59. Terrell Davis        1996 |    0   0 | 1538  13 |  310   2 | 149
 60. Earl Campbell        1980 |    0   0 | 1934  13 |   47   0 | 149
 61. Fran Tarkenton       1975 | 2994  25 |  108   2 |    0   0 | 148
 62. Randall Cunningham   1988 | 3808  24 |  624   6 |    0   0 | 148
 63. Terry Allen          1992 |    0   0 | 1201  13 |  478   2 | 148
 64. Earl Campbell        1979 |    0   0 | 1697  19 |   94   0 | 147
 65. Jerry Rice           1993 |    0   0 |   69   1 | 1503  15 | 147
 66. Roger Craig          1985 |    0   0 | 1050   9 | 1016   6 | 146
 67. Walter Payton        1984 |    0   0 | 1684  11 |  368   0 | 146
 68. Mark Clayton         1984 |    0   0 |   35   0 | 1389  18 | 145
 69. Ken Anderson         1975 | 3169  21 |  188   2 |    0   0 | 145
 70. Jerry Rice           1989 |    0   0 |   33   0 | 1483  17 | 145
 71. Neil Lomax           1984 | 4614  28 |  184   3 |    0   0 | 144
 72. Jim Kelly            1991 | 3844  33 |   45   1 |    0   0 | 144
 73. Thurman Thomas       1989 |    0   0 | 1244   6 |  669   6 | 143
 74. Walter Payton        1979 |    0   0 | 1610  14 |  313   2 | 142
 75. Priest Holmes        2001 |    0   0 | 1555   8 |  614   2 | 142
 76. Cliff Branch         1974 |    0   0 |    0   0 | 1092  13 | 142
 77. Brett Favre          1994 | 3882  33 |  202   2 |    0   0 | 141
 78. Emmitt Smith         1991 |    0   0 | 1563  12 |  258   1 | 141
 79. Neal Anderson        1989 |    0   0 | 1275  11 |  434   4 | 141
 80. Jerry Rice           1994 |    0   0 |   93   2 | 1499  13 | 141
 81. Chuck Foreman        1974 |    0   0 |  777   9 |  586   6 | 140
 82. Barry Sanders        1989 |    0   0 | 1470  14 |  282   0 | 139
 83. Fred Taylor          1998 |    0   0 | 1223  14 |  421   3 | 139
 84. Wilbert Montgomery   1979 |    0   0 | 1512   9 |  494   5 | 139
 85. Emmitt Smith         1993 |    0   0 | 1486   9 |  414   1 | 138
 86. Isaac Bruce          1995 |    0   0 |   17   0 | 1781  13 | 138
 87. Ricky Watters        1996 |    0   0 | 1411  13 |  444   0 | 138
 88. Eric Dickerson       1986 |   15   1 | 1821  11 |  205   0 | 137
 89. Ron Johnson          1972 |    0   0 | 1182   9 |  451   5 | 137
 90. Garrison Hearst      1998 |    0   0 | 1570   7 |  535   2 | 137
 91. Barry Sanders        1994 |    0   0 | 1883   7 |  283   1 | 137
 92. Ron Johnson          1970 |    0   0 | 1027   8 |  487   4 | 136
 93. Scott Mitchell       1995 | 4338  32 |  104   4 |    0   0 | 136
 94. Thurman Thomas       1990 |    0   0 | 1297  11 |  532   2 | 136
 95. William Andrews      1983 |    0   0 | 1567   7 |  609   4 | 134
 96. Eddie George         2000 |    0   0 | 1507  14 |  453   2 | 133
 97. Herman Moore         1995 |    0   0 |    0   0 | 1686  14 | 133
 98. Billy Sims           1981 |    0   0 | 1437  13 |  451   2 | 133
 99. Sterling Sharpe      1992 |    0   0 |    8   0 | 1461  13 | 132
100. Charles White        1987 |    0   0 | 1374  11 |  121   0 | 132