Hiroki and the lack of strikeouts

Hiroki Kuroda has had a bit of an up and down season. He’s had some stinkers and some gems, and his last start against the Mariners on Friday night was successful in that he gave up just two runs, but he walked three while only striking out two and allowing two homers, the second game this year in which he’s allowed more than one homer. Overall, his HR/FB% is at 14.6, which would be the highest of his career by a lot (2011, 11.3%). He’s also got a career high BB/9 at 3.14 (career 2.16) and a career high BB% at 8.2 (career 5.8). His strikeouts are pretty down, too. After sitting over 7 K/9 and at just over 19% in 2010 and 2011, Kuroda’s down to 5.02 K/9 and a 13.2% K percentage. This is definitely the most alarming trend we’ve seen from Kuroda. The control is concerning and so are the home runs, but the latter will likely come down and the former can be mitigated by strikeouts and ground balls; to Kuroda’s credit, his 48.6% groundball rate is definitely acceptable and exactly matches his career rate. Let’s take a look at the strikeout numbers pitch by pitch in 2011 and 2012, and see if we can find out where exactly Hiroki’s problem has been. Numbers, as always, via Brooks Baseball

2011:

2012:

Let’s break this down pitch by pitch. On the fastball, Kuroda’s getting whiffs on swings a whopping 8.25% fewer times than he did last year. The pitch’s groundball percentage is also way down, 10.54% to be exact. On the plus side, though, Kuroda hasn’t given up a homer on old number one thus far.

The sinker is a bit of a mixed bag. While whiff/swing is way down (5.73%) and HR/FB is slightly up (1.01%), that pitch is still doing what it should be doing and getting a metric ton of grounders (up 8.95% from 2011).

Whiff/swing and GB% aren’t changed much on the sinker, but the HRs are way up, just under 10%.

The curveball has led to many more homers and many fewer grounders this year, and like it was rumored to be (and was in 2011), Kuroda’s best pitch in 2012 has been his splitter, with its ridiculous whiff/swing, great GB%, and complete lack of HRs.

Looking over this data, we can see that Kuroda is having the most trouble with his slider and his curveball. The home runs are coming on those pitches, which tells us he’s most definitely not locating those pitches well. And while it hasn’t led to home runs, Hiroki’s fastball has not been effective enough. The low whiff/swing tells us that he’s either not getting the same velocity behind the fastball or that it’s located poorly enough that the batters are laying off of it. Kuroda has thus far lost a bit off the fastball. Last year, it averaged 92.68 MPH; so far in 2012, it’s averaged 91.49 MPH. His ball percentage has also risen to 50% from 41.57% last year. Like all pitchers in the history of baseball, Kuroda’s going to need to start locating his fastball better if he wants his other pitches to be successful.

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