Maybe We Should All Learn the Split-Finger

Swinging strikes are the best. The batter tried to make contact and failed in a head-to-head matchup of will and strength and coordination. That moment is also great, statistically. Swinging strike rate is a per-pitch metric — meaning they become meaningful much faster than per-plate-apperance metrics — and it represents the closest proxy we have to ‘stuff’ that’s easily available.

That said, the fastball is still king, and it has the lowest swinging strike rate of any pitch. The league throws the pitch almost 60% of the time, after all. And if you’re throwing them as much as Shelby Miller and Jordan Zimmerman throw their fastballs, your swinging strike rate is going to suffer. That’s how two great young pitchers have such modest swinging strike numbers.

Is it possible to judge how many more strikes a pitcher with a certain arsenal is getting over a mythical pitcher (Average McAverageson) with the same arsenal where every pitch is league average? Yes. Yes it is.

Thanks to one of my favorite posts to link to, a great library piece by Harry Pavlidis that provides swinging strike benchmarks for each type of pitch, we can actually take a pitcher’s arsenal and create a sort of “expected” swinging strike rate based on how often they throw each pitch. Fairly straight-forward actually.

Of course, the pitchers that find themselves at the top of this list of qualified starters from 2013 are just pitchers who have multiple great pitches. I mean, Pitcher McPitcherson stands atop the qualified leaderboard. (Starters showed a league-wide 8.7% swinging strike rate in 2013.)

Name FA% xswSTR swSTR diff
Matt Harvey 0.576 0.096 0.125 0.029
Cole Hamels 0.539 0.097 0.120 0.023
Kris Medlen 0.151 0.087 0.110 0.023
Felix Hernandez 0.28 0.086 0.107 0.021
Patrick Corbin 0.166 0.086 0.107 0.021
A.J. Burnett 0.461 0.086 0.106 0.020
Anibal Sanchez 0.323 0.106 0.124 0.018
Yu Darvish 0.292 0.108 0.126 0.018
Max Scherzer 0.538 0.102 0.120 0.018
Clayton Kershaw 0.606 0.096 0.114 0.018
Stephen Strasburg 0.487 0.089 0.106 0.017
Julio Teheran 0.47 0.090 0.105 0.015
Homer Bailey 0.395 0.092 0.107 0.015
Jose Fernandez 0.532 0.086 0.101 0.015
Zack Greinke 0.397 0.091 0.104 0.013

There might be a couple overachievers on this list — Kris Medlen and Patrick Corbin both do more than a pitcher would with an average version of their arsenals, but they look a little out of place on this list — but by and large, the pitchers on this list are all excellent. They have excellent pitches! Amazing!

Perhaps the bottom of the list will be more enlightening.

Name FA% xswSTR swSTR diff
Jeremy Guthrie 0.355 0.104 0.051 -0.053
Kevin Correia 0.182 0.108 0.059 -0.049
Bronson Arroyo 0.017 0.103 0.060 -0.043
Eric Stults 0.448 0.105 0.071 -0.034
Joe Saunders 0.138 0.092 0.061 -0.031
Kyle Lohse 0.15 0.102 0.073 -0.029
Yovani Gallardo 0.291 0.097 0.069 -0.028
Mike Leake 0.118 0.093 0.067 -0.026
Mark Buehrle 0.304 0.094 0.069 -0.025
Kyle Kendrick 0.087 0.065 -0.022
Scott Feldman 0.028 0.091 0.072 -0.019
Travis Wood 0.363 0.095 0.077 -0.018
Ubaldo Jimenez 0.335 0.106 0.088 -0.018
Chris Tillman 0.499 0.097 0.079 -0.018
Matt Cain 0.355 0.103 0.086 -0.017

There are some surprises on this list, but for the most part it’s the Unimpressive Stuff list. The top guys on this list have representative offspeed offerings, but until you get about five or six deep, there isn’t a pitch that you could hang your hat on. Many of these pitchers throw a two-seamer primarily, as you can see the four-seam fastball percentages are pretty low, with Kyle Kendrick pulling up the rear. And in general, this group seems to survive on command — they’ve got a 6.7% walk rate as a crew. If you don’t have stuff, you better be able to put it where you want.

At first it was very surprising to see Matt Cain show up here. But then I looked at his per-pitch peripherals last year, and there it was. Only the change-up, of his five pitches, had an above-average swinging strike rate. All of them are close to average… Well, it could have been a one-year blip. His fastball actually used to get a lot of whiffs. Back in the halcyon days of 2012.

And put this in your back pocket: The under-performer with the highest actual swinging strike rate just added a split-finger this year.

Maybe most interesting are the pitchers that, in 2013, featured exactly the swinging strike rate a pitcher with an average version of their arsenals would feature.

Name FA% xswSTR swSTR diff
Jeremy Hellickson 0.33 0.096 0.096 0.000
Hisashi Iwakuma 0.386 0.103 0.103 0.000
Rick Porcello 0.222 0.086 0.086 0.000

Weird, huh? Jeremy Hellickson gets there by having two below-average pitches, one average pitch, and one outstanding pitch. But it’s no brain-buster to say he’s an average pitcher — his FIP was right on the league average last year. As good a pitcher as Rick Porcello is, he’s actually average across the board — where his sinker gets a few more whiffs than usual, his new curve (which helps him bust platoons) is worse than average and drags him back to average. He’s about ground balls at his core, anyway, so swinging strikes may not be his goal.

But Hisashi Iwakuma. He’s not about grounders in the same way at least. He had a gaudy swinging strike rate even (10.3%, good for eighth among qualified starters in the American League last year). It’s a little strange to say that he did just about as well as a major league pitcher throwing his mix of average pitches would do. But on a per-pitch level, he has two above-average pitches by whiffs — the four-seam and the split-finger — and his slider, sinker and curve are all below-average by whiffs.

With split-fingers enjoying the best whiff rates in baseball — a 16.6% swinging strike rate built on the highest swing *and* whiff-per-swing rates — this does illustrate how a pitcher with a good four-seam and split-finger can make his entire arsenal play up, even if the rest of the pitches are sub-par. After all, Iwakuma’s swinging strike rate would have been expected of someone who threw a mix of entirely average pitches that included an average split-finger. And yet his swinging strike rate was in the top ten. Maybe we should all learn split-fingers. Maybe Masahiro Tanaka is about to outperform his projections.

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Graphs: Baseball, Roto, Beer, brats (OK, no graphs for that...yet), repeat. Follow him on Twitter @enosarris.

21 Responses to “Maybe We Should All Learn the Split-Finger”

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  1. Matt says:

    Really interesting article, fascinating stuff. Any similar research on relief pitchers? One would figure (with anecdotal evidence, initially) that Koji Uehara would fare well in this regard.

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  2. benagain123 says:

    keep Freddie freeman for a 7th round pick, or keep Goldshcmidt for a 4th round pick?

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  3. Franco says:

    Boooo, how can any Tommy Hanson article not mention Cyborg Tommy Hanson?

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  4. Patrick Star says:

    Matt Harvey :(

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  5. John Dewey says:

    Many people say the split-finger causes injuries similar to the slider. I’m not sure if people have done studies on the relationship between splitter usage and amount of time missed from injuries, but this could be an answer.

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  6. Roger Craig says:

    There are plenty of pitchers who have based their arsenals around a solid fastball and a split. Mike Scott in 86, Jack Morris, Dave Stewart, Clemens, Bryan Harvey, Tom Henke, Hideo Nomo. The key has been using the 4 seamer high in the zone and then changing the eye level with the split that has very similar rotation. Based on movement, Iwakuma likely places his right thumb on the side of the ball, giving it the fade movement from lefties. Many pitchers place the thumb under the ball causing a more definitve downward drop.

    I believe many blame the split and it’s cousin the forkball for elbow injuries.

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    • Balthazar says:

      I don’t know where Iwakuma places his thumb in using the split. His preferred location is a bit different than you suggest. Iwakuma located it very consistently in the very bottom of the strike zone with the motion dropping out of the zone. It starts off too clearly a strike not to swing at, but would be very hard to make contact with even if it was a two-seamer—and it’s NOT because the pitch just drops away from contact. Even if a very few guys got the bat on the ball it’s just a multi-hop grounder. Throwing it so low, one would expect a high percentage of called balls on it, but Iwakuma didn’t seem to have that difficulty. If he missed, he’d just come back and put another split through the bottom four inches of the strike zone.

      But yeah, Iwakuma does throw his fast ball up, even though it’s only about 91 mph now. The pattern you suggest, FB up, SPL starting up but diving, is the way to work it. And Iwakuma’s fastball played up better exactly because batters had to be thinking about the split down low and tended to get tied up on the high sorta-fastball. Iwakuma also uses a curve to change the look batters were getting. I was very impressed with Iwakuma’s command, and willingness to sequence his pitches intelligently.

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    • Balthazar says:

      Oh, and ad Kazuhiro Sasaki, the reliever to your list of split-finger pitchers whose elbows disintegrated. He was highly effective when he could throw the split, but he had to throw it a high percentage therefore, and his elbow repeatedly broke down. He and Bryan Harvey are perhaps the two best examples of guys highly dependent upon throwing the splitter who seemed to have their careers end early because of directly associated injuries.

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  7. Nathaniel Dawson says:

    The split-finger is a pitch that has long been perceived as very harmful to a pitchers arm.

    One example here:

    There’s no doubt that it can be a very potent pitch in a pitcher’s arsenal, but until/unless major leaguers can feel comfortable throwing it without fear of damaging their elbow, we probably won’t see a big revival of the pitch.

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    • SimonSays says:

      My coaches always told me if you are not a major leaguer or one pitch away from a major league career, the splitter is not for you. The strain on your arm is because your forearms are under intense strain as you go through the violent motion we call throwing. This causes all sorts of bad things that lead to things like Tommy John surgery, carpal tunnel, and cubital tunnel.

      Splitters are also incredibly difficult to control. Your forearms are really going all out trying to keep the ball in control until release, and your fingers need to be squeezing at the correct pressure or it will just turn into one of either (a) a slow two-seamer without much movement or (b) a forkball/knuckball kind of thing that slips out and makes a beeline for the batter’s head.

      But when you throw a splitter well, it’s incredible. I don’t know if it’s hittable. It’s literally the same motion and basically the same spin as a fastball (unlike a slider or curveball that can sometimes be seen out of the hand). The best way to describe it is a two-seamer with a bomb attached. Even catching splitters is hard because they’re so explosive.

      It is very much a high risk, high reward pitch.

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    • Balthazar says:

      Yeah, the reputation of the split as an injury-inducing pitch has definitely led to a decline in usage. Pitchers seem to have gone back to throwing the slider more . . . which was _the_ pitch with an injury-inducing reputation (elbows also) before the split-finger came along.

      I would like to see the split-finger used more in MLB. To me, the question is frequency. Someone throwing the split a lot is going to have better control of it but higher risk. Used as a low-frequency, put-away pitch, though, one would get the best gain with the least risk. It’s doubtless hard not to use an unhittable pitch, but that might still be the best way to get the pitch into the repetoire of more pitchers.

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      • Mike says:

        The problem is that even if a pitcher limits the amount of times he throws the pitch in live action, he still has to throw it about a dozen times in bullpen sessions for every single in-game pitch. Its not usage of a splitter that wrecks an arm, its learning and maintaining the pitch that wears the pitcher down.

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  8. ankle explosion hr celebration says:

    it may be verboten to cite a FG competitor, but Iwakuma is one of the guys that popped out as benefiting from having a large variety of pitches in this recent BPro article:

    I wonder if that (i.e. entropy) explains some of the difference in SwSt% vs. expected SwSt%, in that pitchers with lots of entropy become sort of “greater than the sum of their parts”.

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    • ankle explosion hr celebration says:

      Noting, of course, that the latter thought does not much apply to Iwakuma, since he is apparently exactly the sum of his parts. But perhaps it does to other pitchers.

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  9. ghug says:

    The comment in the video about the Mariners having the best fielding percentage in the majors made my day.

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  10. TanGeng says:

    Those numbers aren’t really % values right? Otherwise they’re all much too small.

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  11. hp says:

    probably a silly question but is a foul ball considered a swinging strike?

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  12. BobbyWestside says:

    What do you think about Patrick Corbin this year for fantasy? Will his year end numbers be better or worse than last years?

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