Win Shares - Criticism of Win Shares

Criticism of Win Shares

• Players cannot be awarded "loss shares", or negative win shares, by definition. Some critics of the system argue that negative win shares are necessary. In defense of the system, proponents argue that very few players in a season would amass a negative total, if it were possible. However, critics argue, when one player does amass a negative total, he is zeroed out, thus diminishing other players' win-share totals. In an attempt to fix this error, some have developed a modified system in which negative win shares are indeed possible.
• The allocation of win shares 48% offense and 52% defense is justified by James in that pitchers typically receive less credit than hitters in win shares and would receive far too few win shares if they were divided evenly.
• One criticism of this metric is that players who play for teams that win more games than expected, based on the Pythagorean expectation, receive more win shares than players whose team wins fewer games than expected. Since a team exceeding or falling short of its Pythagorean expectation is generally acknowledged as chance, some believe that credit should not be assigned purely based on team wins. However, team wins are the bedrock of the system, whose purpose is to assign credit for what happened. Win shares are intended to represent player value (what they were responsible for) rather than player ability (what the player's true skill level is).

Within the sabermetric community there is ongoing debate as to the details of the system. The Hardball Times has developed its own Win Shares, as well as a number of derivative statistics, such as Win Shares Above Bench, Win Shares Percentage, Win Shares Above Average, and All Star Win Shares.