When the Yankees signed Hiroki Kuroda in January, it wasn’t met with much fanfare, being overshadowed by the Jesus Montero-Michael Pineda swap. Despite success in Japan and with the Dodgers, there were some concerns given the Yankees track record with pitchers moving from the NL (cases in point: Carl Pavano, Javier Vazquez). Additionally, past failure with Japanese hurlers Hideki Irabu and Kei Igawa left a bad taste in Yankees fans mouths. Regardless, Kuroda’s 2012 is an example of how the past isn’t always indicative of the future.
After last night’s dominant complete game two-hit shutout of baseball’s top run scoring team, Kuroda lowered his ERA to 3.06. FIP, xFIP, and SIERA have Hiroki at 3.71, 3.69, and 3.68. While these are higher than his ERA, he still clearly has been very effective. His strikeout rate is slightly down from the past two seasons (19.6% and 19.2% K rate in 2010 and 2011, 18.8% in 2012) which may account for a partial increase for the ERA estimators.
What’s been the driving success of Kuroda’s season with the Yankees? His splitter has been absolutely unhittable. In terms of pitch values, it’s the third best in the game behind Dan Haren and Jeff Samardzija. Yes, there are only twelve pitchers who throw the a split according to PITCHf/x, but taking a closer look, it is clear to see why it’s been such an effective pitch. In his career, it has always been a great option for him, as hitters only have a 79 wRC+ and .264 wOBA. This year, however, it’s on a different level: 35 wRC+ and .212 wOBA. Taking a look at batted ball types agains the split, 62.1% of balls in play are grounders, while just 13.8% are in the air. Line drive rate is a paltry 15.5%. These are big improvements versus prior years. This weaker contact likely means that he’s improved the splitter’s “nastiness”, and PITCHf/x movement data complies. See the movement chart for this season below:
Now, take a look at how this season’s splitter stacks up to his career entering 2012:
It looks like there is a slight trend for Kuroda keeping his splitter down compared to seasons past, albeit there are more outliers in 2012. Some of these outliers could be misclassified pitches (perhaps sinkers). More noticeable is the fact that the ball is really tailing away from lefties and busting in on righties compared to prior years.
The slider has also been a formidable pitch for Hiroki. He’s thrown it more frequently than in recent years, already 632 times compared to 604 last season. For good reason- wOBA against is a mere .289 and wRC+ is 89. It actually has been a lot better in the past (.263 wOBA and 70 wRC+), thanks to a 12.8% HR/FB rate on the pitch in 2012, compared to 8.7% career. Still, it’s been his best strikeout pitch, accounting for 51 of his 121. The splitter is behind it, with 33.
His strong arsenal isn’t done there- his sinker has also been highly effective. Pitch value rates his sinker as the cream of the crop this season, just beating Jake Westbrook. Batters have a 91 wRC+ and .304 wOBA on the pitch. While it hasn’t been as dominant as the split and slider, there have been mostly singles off the pitch, so no real damage. His ground ball rate on the sinker is 57.5%, a bit above his 56.1% career mark. Can’t do too much damage on a bunch of singles, especially with a BB/9 of 2.15.
Another key to success for Kuroda? As alluded to in the last paragraph: keeping the ball on the ground. An overall 51.9% of batted balls are hit into the ground, while just 29.4% are airborne. Both of these rates are more than 2% better than career norms. Line drive rate (18.6%) is slightly below his career (19.2%), and his .279 BABIP is in line with his .281 career BABIP. So, it’s not like Kuroda’s gotten lucky. In fact, he may be getting a bit unlucky on fly balls with a 11.5% HR/FB compared to 9.6% career. On the surface, it may seem that this can be attributed to pitching in Yankee Stadium, but 9 of his 16 home runs allowed have actually been on the road.
Kuroda has done all of this when the Yankees have needed him most. Injuries to CC Sabathia and Andy Pettitte, and inconsistency from Ivan Nova and Phil Hughes could have really been detrimental to the club. Kuroda has kept the rotation afloat, especially his last ten starts dating back to June 25. Over that timeframe, Pettitte and Sabathia (twice now) have gone down, all the while he’s posted a 2.42 ERA in 70 2/3 innnings, and the club is 8-2 in those starts.
Hiroki has done enough to prove that he’s capable handling the AL East, and has made everyone forget about past Japanese pitching busts in Irabu and Igawa. He absolutely deserves to be brought back in 2013. Another one year deal should be reasonable given that he’ll be 38 next year, but he certainly deserves a raise from $10M in 2012. This type of deal is perfect given the austerity budget plans for 2014. Brian Cashman has to be praised for this acquisition, and hopefully the two sides can work out a contract for next season as well.