[1]: 169 The encyclopedia contains seasonal and career statistics in numerous categories for every Major League Baseball player, as well as historical, opinion, and year-by-year essays.
[1]: 167 These included thousands of miscalculations by earlier statisticians, typographical errors made by the original scorekeepers, and even "phantom" players who did not actually exist and were added to a box score incorrectly, Lou Proctor being a notable example.
[1]: 167 In addition, Thorn and Palmer corrected mistakes not commonly accepted by the baseball community, such as the discovery that Ty Cobb actually garnered 4,189 hits, not 4,191, or that Walter Johnson in fact had 417 career wins, not 414 or 416.
Their most important new statistic was on-base plus slugging (OPS, today commonly seen on baseball cards and scoreboards)[1]: 233 for all batters since 1876 for whom bases on balls were recorded.
As OPS+ the statistic was normalized for season and home park, thus permitting direct comparison of the impact of players across generations, such as Babe Ruth in 1927 and Barry Bonds in 2001.
The Roster section included the regular players, pitchers, key substitutes, and managers for all 2,010 team seasons in the history of professional baseball going back to 1871.