Inside Hiroki’s turnaround

 

For more insight on Kuroda, visit RAB and read Joe’s piece on him from yesterday.

April and May weren’t necessarily too kind to Hiroki Kuroda. He had an up and down start to his Yankee career and generally left us wanting more, despite some good starts sprinkled in. Through April and May, Kuroda had a respectable 3.96 ERA, but his FIP sat at an ugly 5.15 and batters were hitting pretty well off of him: .267/.328/.445/.773 with ten homers in 61.1 innings. He didn’t walk many–21–but he didn’t strike out many either–37–and gave up a fair amount of homers–ten. June and July, though, have been much better. In the last two months, including last night’s game, Kuroda’s thrown 68 great innings. His ERA has been 2.78 and his FIP has been 2.74. Hitters have hit just .223/.271/.359/.630. Kuroda’s issued just 13 walks in that time, while striking out 66 and surrendering just 5 HR. What caused the turn around? Kuroda’s certainly a veteran pitcher who’s going to make adjustments, but what were they?

Here’s some data via Texas Leaguers through April and May. First up, we take a look at Kuroda’s most used pitch types. After that, we see the overall results of all the pitches Kuroda threw from April and May.

 

Pitch type Strike% Swing% Whiff% Foul%
Sinker 70.5 45.4 3.8 16.5
Slider 60.3 42.5 11.5 17.9%
 Result Percentage
 Ground out  21.67
 Strikeout  14.07
 Walk  7.60
 Home Run  3.80

Now, let’s take a look at the same tables, but adjusted for June and July:

Pitch Strike% (change) Swing% (change) Whiff% (change) Foul% (change)
Sinker 72.7 (+2.20) 52.6 (+7.2) 5.5 (+1.7) 24.7 (+8.2)
Slider 70.3 (+10) 54.4 (+11.9) 18.9 (+7.4) 16.6 (-1.3)

 

Result Percentage (change)
Ground out 24.63 (+2.96)
Strikeout 24.26 (+10.19)
Walk 4.41 (-3.19)
Home Run 1.84 (-1.96)

The only thing that’s changed negatively over the last few months has been the decline in foul% against his slider. But, given the big increases in strike percentage and whiff percentage, it doesn’t really seem that guys are squaring the ball up against Hirok. On the results side of things, ground outs are up, strikeouts are WAY up, and walks and homers are down. Things have been trending in the right direction for Kuroda and we’ll certainly hope they continue to do so. So long as that slider continues to be an effective pitch, I don’t see him slowing down.