A few weeks ago I posted about BABIP, and it’s effect on a pitcher’s apparent ability. Pitchers are often the beneficiaries of luck, whether it be good or bad, and the Nationals’ Jordan Zimmermann appeared to be suffering from the bad kind. On the other hand, White Sox pitcher Gavin Floyd burst onto the scene last season with a 17-8 record and 3.84 ERA, and crazy-good numbers in has last 8 starts this season. Eric Karabell gave him some love in an ESPN article recently, but is it deserved?
Posting a 0.802 OPS against and giving up 5.37 runs* per nine innings, at first glance one might have guessed that Zimmermann was headed for a minors stint. Since then, however, he and his defense have allowed just three runs in nearly 18 innings with an OPS against of 0.555. The difference? His strikeout and walk numbers have remained fairly constant, but his BABIP has plummeted nearly 100 points and he’s giving up less home runs per plate appearance. The rest of the way, look for his OPS against to balance out toward 0.700 and his runs allowed to hang around 3.8 per 9 innings.
Karabell notes in his article that Floyd has been stellar in his last 8 starts, with an ERA of only 1.39. But looking deeper, there are some telling numbers that predict his immediate one-way ticket to mediocrity. First of all, his BABIP over those past 8 starts is just 0.220. He’s suddenly allowing more ground balls, and while a pitcher has some control over this, it’s not likely that he’s changed anything mid season. And finally, his homers per fly ball ratio is at about 3%, yet his career average with the Sox is closer to 10%. With Floyd, we expect a more level BABIP, normal groundball/flyball ratios, and an increase in homers per flyball. I estimate a 0.750 OPS against and approximately 4.6-4.7 runs allowed per game.
Remember, win-loss records and ERA hide so much of the true value of a pitcher. Always pay attention to luck figures such as BABIP and HR/flyball, as well and suspicious spikes in the more controllable stats such as HR/inning, groundball/flyball ratio and strikeout-walk rates.
*Note that these are all runs allowed numbers, not earned runs allowed.