Introducing Win Shares Above Average

Win Shares have been updated through games of May 21st, and I’ve made a couple of important changes. First, I’ve credited players with negative Win Shares if their performance falls below the minimum standard. In the original methodology, those players had their Win Shares zeroed out. This is an important change, as I described during the offseason.

There is one caveat, however. I did not create negative Win Shares for the Expos, because their offense, at this point of the season, is historically bad and throws off some of the calculations. I’ll try and fix that in the next iteration.

Also, I’ve added each player’s “Expected Win Shares”, which is the number of Win Shares that player would be expected to achieve given his playing time. In other words, it’s the average baseline for that player. You can read more about the methodology in this article.

Finally, I calculated each player’s Win Shares Above Average, which is Win Shares minus Expected Win Shares. This is a better measure of a player’s contribution to his team, as explained over at Baseballgraphs.

These are important and, in my mind, necessary changes to the Win Shares system. I’ll tweak the system a little more during the year, but if you have any questions about these changes after reading the articles, please drop me an e-mail.