Joe Kelly is better than Jake Westbrook, but worse than Joe Kelly

From Opening Day until May 30—the end of his Sick Man of the Bullpen period—Joe Kelly had allowed 14 runs in 19 innings. He’d struck out 21 percent of the batters he faced, walked eight percent, and allowed home runs to four percent. His ERA was 6.75.

On June 5 he made his first start of the season, and was so pleasantly adequate that the Cardinals gave him two more that month. Going into last night’s win he’d thrown 59 innings. He’d struck out 15 percent of the batters he faced, walked nine percent, and allowed home runs to one percent. His ERA was 1.83.

Those numbers aren’t bad, but they’re noticeably worse than the composite Joe Kelly his first two years in the majors have built up. Right now he’s a perfect example of what separates rWAR and fWAR: 2.2 in 191 career innings for Baseball Reference, 1.0 for peripheral-focused FanGraphs. Above-average vs. passable.

But lots of pitchers put together implausible and extremely useful hot streaks. Kelly’s unimpressive peripherals wouldn’t be inconvenient at all, except that all of us are busy right now trying to push Jake Westbrook out of the rotation and into the bullpen, in the "big field where he can run around and throw sinkers all day" sense of the word bullpen.

Jake Westbrook and Joe Kelly are not competing for the same spot in the rotation, which is a good thing–if they were we would be forced to think about our poor treatment of Westbrook, instead of just our general distaste for his work. Westbrook’s peripherals are even worse, granted—they’re basically the worst in baseball—but he, too, had a period of time in which he was putting up wonderful results with unimpressive peripherals, and he, too, throws a sinker, and that’s how the Christmas Carol ghosts teach you a lesson.

Jake Westbrook isn’t an omen; Kelly’s peripherals, if anything, bring to mind the good Westbrook, who ate a lot of innings, even if he had trouble digesting them. But Jake Westbrook is still a notice, if not quite a warning–a reminder that the key to our appreciation of how Joe Kelly is pitching right now is the unstated assumption that he’ll pitch better than this, and that he’ll have to to get these results.

Which is fine: His fastball’s averaging 95 miles an hour this year. It certainly feels like he could be this good.