A closer look at Hiroki Kuroda

I don't know what he's throwing but I know it will be low in the zone.

Since 2009 the job of top pitcher on the Yankee staff has been taken. From that season through 2011 CC Sabathia has been everything the Yankees hoped for, one of those rare free-agent binges that works out perfectly. CC managed about 230 innings of pitching dominance each of those seasons, perhaps setting an unsustainable standard.

This season has gone differently. After establishing himself as a work horse, Sabathia has had two stints on the DL. His numbers have remained solid, but they are not as strong as they have been. The main drivers of this are a less effective fastball and letting a few more home runs leave the park. The net effect, however, is that CC has given the Yankees fewer innings this season, and the innings he has given them haven’t been quite as strong as they were before.

Enter Hiroki Kuroda. When the Yankees were making noise about signing Kuroda this off season my reaction was muted. Apart from not knowing much about Kuroda, I also didn’t see how large an impact a number two pitcher could have on the Yankees. Except, in the end, the Yankees didn’t wind up signing a number two. It looks like they signed a number one. Did they?

Kuroda has most certainly exceeded all expectations this season. The most important number Kuroda has put up this year is 183.1, the number of innings he has given the Yankees this year. That’s a lot of quality innings, especially when you consider that CC has only pitched 156 innings this year. And they have been quality innings. For his career Kuroda has a 3.37/3.61/3.63 pitching slash line, mostly accumulated in the NL West. In his one season in AL East so far he’s managed a 3.04/3.83/3.70 line. While the FIP and xFIP aren’t lights out, there’s no arguing with the success and the ability to take pressure off the bullpen.

Kuroda does his damage as a ground ball pitcher (which helps explain the difference between his ERA and peripherals). According to PitchFX his most potent offerings are his sinking fastball and his split fingered fastball, worth 16.2 and 3.7 runs respectively. (Note, that may be a classification error, as those are similar pitches. Kuroda may be manipulating the same basic pitch to break differently.) He also throws a plus slider worth 2.3 runs. The pitches range in speed from 84mph (slider) to 92 mph (sinker).

After taking a closer look at these numbers it becomes clear why Kuroda is an effective ground ball pitcher. His best three offerings are similarly low in the zone, but have different breaks and speeds. It allows him to have a pitch break low in the zone on both sides of the plate. That’s a recipe for a large number of grounders and a fair number of strikeouts as well.

It is not a recipe to produce a tremendous amount of fWAR. In fact, while Kuroda’s season has been recognized as being better than CC’s, Fangraphs doesn’t think so. Fangraphs says that CC has been worth 3.9 fWAR this season while Kuroda has been worth 3.4 fWAR. Given how much emphasis fWAR puts on strikeouts, it makes sense that CC will get the nod here. He’s striking out far more batters than Kuroda (9.06 per nine versus 6.63). Advanced metrics will smile favorably upon that.

For my part I don’t think there’s much argument. While metrics such as FIP and xFIP are valuable, at the end of the day Kuroda has given the Yankees more innings than any other pitcher on the team and allowed fewer runs to score during that time. For those simple reasons he has been the Yankees best pitcher this season. With any luck, he’ll combine with a fully healthy CC to give the Yankees the best 1-2 punch in October they’ve had since 2009.