At his blog, Pat Lackey has been making a big deal (as he should be) of the Pirates’ third order winning percentage. All year, the Pirates’ win percentage has been markedly higher than their third order winning percentage. That gap has narrowed, but remains at .050, which is the difference between .563 and .513. Put in terms of wins, that is the difference between being 49-38 and 45-43. That is a huge difference in baseball.
Third order winning percentage has often been a better predictor of future results than winning percentage, which is why this is important to the Pirates. Based on this, it seems likely that their performance may fall off a bit in the second half of the season.
All arguments and statistics, however, possess bias. In order to better understand the Pirates’ chances of continuing to outperform their third order winning percentage, I will try to examine these biases and then determine whether they affect how the statistic applies to the Pirates. If they do not, then we could be in for some trouble. If they do, then we could be seeing the start of something special.