Why Hiroki Kuroda’s Performance on Monday Was So Awesome

Before we get into specifics, look at this:

Hiroki Kuroda 2010: 162 IP, 3.39 ERA/3.28 FIP/3.61 xFIP.

Putting it bluntly, Kuroda has been an unsung hero of the 2010 season. He replaced Randy Wolf’s production easily. WAR has been divisive on him, but 3.5 Fangraphs WAR. 2.0 B-R WAR.

But ignore the WAR.

Kuroda’s always been effective for a number of reasons: he does a lot of things very well. High ground ball-rate (51% this year), high K-rate (7.78), low BB-rate (2.22). None of these stand out as elite, but they’re all well above-average. His LOB% is below 70, his BABIP is at .301 and his HR/FB ratio is at 7.8%, which explains why xFIP loves him. He’s doing very well and without the aid of luck.

Then looking at contact percentages, he’s top 20 in the following (where the number is better when it’s higher): Swing (48.6%), Swinging Strike (10.2%);

And where the number is better when it’s lower: Contact (77.6%) and Outside Zone Swing (35.2%).

Because of that latter one, he has one of the worst rates of pitches inside the strike zone, but that may be one reason why he’s so successful: he gets a lot of dudes to swing at strikes outside the zone.

He’s also in the top 30 of Outside Zone Contact (64.0%) and Inside Zone Contact (87.3%); both are better when they’re lower.

Again, he does a lot of things very well.

So last night, this is what everything looked like.

Kuroda's pitches from one-hitter, Aug. 30, 2010

Three swinging strikes with the fastball, three with the sinker and four with the slider. Gameday seems to confuse the sinker and his split-finger fastball, but know that whatever it is, it’s thrown at about 92 mph and has some badass horizontal break. (I’m gonna call it the splitter here on out).

Anyway, that’s a very healthy mix of pitches from Kuroda. The break difference on those two is pretty big too and looking at it from one of BrooksBaseball.net’s other angles, check this shit out:

Kuroda's h-movement, Aug. 30, 2010

Kuroda's h-movement, Aug. 30, 2010

For that image, you’re looking at it from above the catcher.

So basically Kuroda’s fastball moved straight and to the right while his slider and splitter moved in completely opposite directions at different speeds. Sorry to not have the evidence to back it up, but Kuroda’s movement on each pitch hasn’t been that clean and crisp all year. All three pitches are clearly delineated, start at different points and end at different points. The same goes with vertical movement; each ended at a different vertical break–and something that may have aided Kuroda: the splitter and slider broke almost a full inch less vertically than usual.

Average V-movement
Splitter: 4.3 inches
Slider: 1.5 inches

V-Movement Monday night:
Splitter: 3.3
Slider: 0.8

Also note that the four-seamer broke 7.77, just a bit above his 7.3 average.

Now I know this is anecdotal, but Kuroda seems to get into more trouble when the vertical movements on his pitches are closer together. See here and here and here and here and here. These are the five worst outings of the year for Kuroda. Four of those 5 games, his sinker was above +4 inches of vertical movement and 4 of those 5 games, his fastball was below 7 inches of vertical movement. So yes, when his sinker/splitter doesn’t sink and his fastball doesn’t go up, he’s likely in trouble.

I don’t think it’s any surprise if we found out that vertical movement had the most to do with success in baseball, but we’ll find out more on that later.


One more thing to take notice, here’s what Kuroda’s pitch values looked like before Monday:

3.5 four-seamer/7.9 slider/-0.1 curve/2.2 splitter

Then after Monday:

6.7 four-seamer/8.8 slider/-0.1 curve/3.1 splitter

Pretty damn cool.


What I want to find out, and hopefully I can ask a few players on Friday, is how a batter recognizes a pitch he’s sitting on: by speed or by movement or both?


I’m working with Albert Lyu, who writes for thinkbluecrew.com, about doing detailed strike zone plotting for pitchers and hitters. We’re trying to come up with a way to present the value of a pitcher via plotting and it’s been tricky–we’re still in the development stages–but it seems like we have a cool idea for getting something for hitters. Look for it after the season.


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Filed under Los Angeles Dodgers, MLB

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