ERA Doesn’t Always Tell the Full Story


If you look at the box score from last night’s game in Detroit, you’ll see that AJ Burnett gave up 1 ER in 5 2/3 IP, and Rick Porcello gave up 4ER in 6IP. Clearly, Burnett pitched much better, right? That definitely wasn’t the case.

Delving deeper, Burnett faced 24 batters, and while he only yielded 4 hits, the Tigers were only 4/21 on balls put in play. They were pretty unlucky on that end. Burnett also had 4 walks, and stranded every single Tiger runner on base. Since the Tigers hit 10 GB, 5 line drives, and only 1 FB, their BABIP should have been much higher than a measly .188. Using a simple BABIP calculator (.725 for LD, .235 for GB, .140 for FB), even though it’s a miniature sample size, Burnett should have yielded 2.35 hits on ground balls, 3.57 hits on line drives, and .135 hits on fly balls. Add that together, that’s 7 hits for the Tigers, not just 4. As everyone knows, if the Don Kelly line drive falls, the game is much different. If a sprawling Curtis Granderson doesn’t catch the Jhonny Peralta drive, the game is different. That is where the disparity in BABIP is primarily, great defensive plays. For what it’s worth, Burnett’s FIP last night was 6.38, while his ERA was 1.59. Once again, I understand it’s an incredibly microscopic sample, but Burnett definitely got lucky in his performance last night.

Porcello suffered the exact opposite luck. He had a much better ratio of 5-1 strikeouts to walks, and also only suffered 5 hits. The Yankee hits were timely, and of the 8 base runners, 4 of them scored. If you would have told me before the game the Yankees would have only scored 4 runs off Rick in 6 innings, I’d have said that we’d have a pretty good shot of winning the game. While Rick’s 6 ERA is nothing to write home about, his 2.86 FIP shows that he probably shouldn’t have given up that many runs. Most of the time, Rick’s performance independent of his fielders will trump Burnett’s. Usually, the guy with the 2.86 FIP will post the 1.59 ERA and the guy with the 6.38 FIP will post the 6 ERA. Unfortunately for the Tigers, last night wasn’t one of those cases.