Why wins are a useless statistic for judging pitchers

Recently my roomate and I have been talking alot about Andy Pettitte and whether or not he is a hall of famer. The number one statistic that my roomate points to is his career and postseason number of wins. This topic got us into the discussion about whether or not wins are a useful statistic when evaluating a pitcher.

In my opinion wins are a useless statistic for judging pitchers performances. A win(or loss) is much more of a team statistic than an individual statistic. Wins measure whether or not your team scored more runs than you gave up. When trying to figure out whether or not we should use wins to judge a pitcher statistically we need to look at what the purpose of statistics are.

The purpose of a statistic is to evaluate a players performance, either in an individual game or over an entire season or career. Let's use ERA as an example. If pitcher A gives up 3 runs over 9 innings he has a 3.0 era; whereas, if pitcher B gives up 5 runs over 9 innings he has a 5.0 era. Looking at how many runs each pitcher gave up, an outside observer can tell that the pitcher who has a 3.0 era pitched better than the pitcher with a 5.0 era. Now lets look at the same two pitchers. Pitcher A who gave up three runs got a loss and pitcher B who gave up 5 runs got a win. Which pitcher had a better game? Which pitcher had a worse game? By just looking at who got the win or loss you would assume that the pitcher who got the win had the better game and the pitcher who got the loss had a worse game; however, you would be completely wrong. This example shows why wins and losses should not be used to judge a pitcher statistically.

The other major reason why wins and losses should not be used to judge pitchers is that the bullpen has a major effect on the second half of the game. Once a pitcher exits the game while the game is still in progress they no longer have any control over the outcome. If the pitcher leaves with his team winning and then the bullpen blows the lead, the pitcher is no longer credited with the win. On the flip side if a pitcher leaves the game with his team losing, his team makes a comeback and his team wins the original pitcher is no longer credited with a loss. This would cause pitchers who have pitched a bad game to look better and not get a loss and pitchers who have pitched a good game to look worse and not get a win.