Value Approximation Method

From SABR Encyclopedia

Value Approximation Method (VAM) is a baseball statistic invented by Bill James to compare players' seasons. VAM rewards both quality and quantity. VAM emphasizes its imprecise nature in both its name and by being an integer. A poor player who hardly played would have a VAM of 0, 1, or 2 while a league MVP usually is a little below 20. VAM was privately published by James in 1980^[1] and first publicly published in 1982 ^[2].

Method

For pitchers: A) Each pitcher VAM is initially based on his season's games pitched:

 0 for less than 30 G 
 1 for 30-54
 2 for 55-79
 3 for 80 or more 

B) Add value for Innings Pitched:

 0 for less than 40 IP 
 1 for  40-89
 2 for  90-139
 3 for 140-189
 4 for 190-239
 5 for 240-289
 6 for 290-339

etc.