What's up with Hiroki Kuroda? The guy was in contention for the Cy Young award a little less than a month ago, and now he's one of the weakest pitchers in a dilapidated rotation. Yesterday, he struggled in 6.0 innings of work, luckily giving up just 3 runs on 8 hits and 4 walks. But his struggles have exceeded just last night's game. Over Kuroda's last 7 games, he's pitched 41.0 innings with a 6.37 ERA. It's hard to tell exactly what's wrong with Kuroda. Many say that the 38 year old starter has hit a wall at the end of the season, that he looks fatigued. But Kuroda's velocity is actually up. Compared to his first 24 starts of the year, his sinker velocity is up nearly a mph from 92 mph to 92.9 mph. This increased speed can be seen in all of his pitchers, including his splitter, slider, and curveball. That's not entirely surprising, considering how long it takes for a pitcher to reach full strength throughout the year, but you'd expect a fatigued a older pitcher to lose velocity.
Perhaps he's been overthrowing, and thus his command is off. Indeed, the movement on his pitches have changed rather significantly. Though the vertical movement is consistent, the horizontal movement on his four-seam has increased by around 1.3 inches into right-handed hitters, as well as his sinker by .6 inches, and his slider by .8 inches. The curveball and splitter have averaged more movement in towards left-handed hitters, with the curveball gaining .7 inches of movement and the splitter nearly 1.5 inches of movement. So it looks like there's more spin and more velocity, a decent indication of overthrowing. But Kuroda hasn't been too wild on the mound. Through his last 41.0 innings of work, he's allowed just 12 walks, 4 of which came in last night's game.
It is possible, and does often happen, where pitchers have control of the plate, but little command of their stuff. A good example for Yankee fans is Phil Hughes, who has great command of his fastball, but little command of his breaking pitches. It results in low walk rates, but hard hit balls when he misses his spots. Kuroda seems to have this problem. Although he's limiting the walks, he's left pitches up in the zone. It's resulted in hitters tanking his sinker for a .400 batting average and .659 slugging percentage.
I don't think that Kuroda is fatigued beyond productivity. In last night's game, he seemed to settle down in 4th inning after giving up a double and a walk. There was less velocity and better command of his pitches, and it looked like he readjusted his timing. He proceeded to strikeout 5 of the next 7 batters before giving up a home run to Anthony Gose. It's certainly possible that it's just small sample size, but the data and my eyes tell me that this isn't simply a 38 year old pitcher falling apart. He still has velocity and command, but he looks like he's overthrowing at times, particularly high leverage situations, and thus missing his spots.
So the ultimate question is whether or not the Yankees should re-sign him, assuming he wants to come back in 2014. This is the second year that Kuroda has performed poorly at the end of the year, and there is now legitimate concern about his ability to pitch through 200+ innings. There are few better options out there though. Perhaps the Yankees would prefer a similar yet younger pitcher in Masahiro Tanka? But that's a large investment on a risky player. Ubaldo Jimenez offers a similar type of risky investment. Meanwhile, Matt Garza has a recent injury history and he's been awful with the Rangers. Kuroda could be the best option out there, and with so many needs in the rotation for 2014, I wouldn't be against re-signing the right-hander.