We've altered Bill James' original Win Shares formula a bit. Specifically, we've credited players with negative Win Shares, which Bill James doesn't do, and we've toned down the credit that Win Shares gives relievers for saves, which is more appropriate for today's save-happy environment.
We've also included two new Win Share stats. One is Win Shares Above Bench (WSAB). WSAB is a refined approach to Win Shares, in which each player's total Win Shares are compared to the Win Shares an average bench player would have received, given that player's time at bat, on the mound or in the field (listed as Expected Win Shares). This is an important adjustment to Win Shares, as we discovered during the 2003-2004 offseason. The bench player approach is explained in this article. It is essentially 75% of Expected Win Shares for all players except Starting Pitchers, for whom it is 60% of Expected Win Shares.
We've also listed Win Shares Percent (WSP), which is a Win Shares "rate stat" -- a measure of the player's contribution, given his playing time. The math is WS/(2*ExpWS).
If a player has played for multiple teams during this time, his Win Shares are broken out for each team. Note that Position is the one the player has played most frequently during the year. As a result, Fielding Win Shares may include shares that have been earned at other positions. If a player has no position listed, it means he has not yet played in the field this year.