Last night, Jamie Moyer did what it seems Jamie Moyer does best: he dominated the Marlins. In his career, he's 13-2 against the Marlins, with a 2.83 ERA over 95.3 innings. He's even more amazing against them in Miami. There, he's 8-0 against them in 8 starts, racking up a 1.37 ERA in 52.7 innings.
Much is made of Moyer's mastery of the Marlins, but this kind of dominance by Moyer against one team is not unique. With a career ERA of 4.22 over 3,848.3 innings, you would expect Moyer to have some teams he really excels against. Certainly, the Marlins are one of those teams, but there are others as well. Here's a list of the teams that Moyer has a less than 3.00 ERA against over the course of his career:
Based on this list, there's nothing really special about the Marlins. His dominance of them sits comfortably with his dominance over a few other teams. The more important question, that I don't have the answer to, is whether there's some pattern here in the sense that there's anything that these teams have in common. That's a hard question, especially considering that he has performed well against these teams over such a long career (particularly over the Orioles and Rays, against whom he's pitched over a greater span of time than the three NL teams). If there's nothing that these teams have in common, is this just a normal distribution of performance for a player with a 4.22 ERA -- there are going to be some teams he dominates, and this is the list?
On the flipside, there are teams against whom Moyer is horrible. Even though past performance is no guarantee of future results here, I would think hard about skipping Moyer's spot in the rotation if the Phillies ever face the Red Sox again. Here's the same chart as above, but for the teams Moyer has a career 5.00+ ERA against:
Same question here. Is there anything that these teams have in common? With the Phillies, Rockies, and Reds on the list, maybe he's not so good in hitters parks. After all, his career ERA at Citizens Bank Park is 5.04. But also on the list are the Dodgers and Braves, who have had pitchers parks.
Someone with a career ERA of 4.22 over almost 4000 innings is not going to have an ERA of 4.22 against every team. Rather, there are going to be some teams the pitcher dominates. And other teams the pitcher looks like a career minor leaguer. As boring as it is, Moyer's mastery of the Marlins may just be normal statistical variation.