Mankind has invented the wheel. Split the atom. Explored space. It stands to reason that, one day, a legitimately unhittable pitch shall be discovered.

Until then, well, at least there’s one pitch that’s pretty close.

This being the super-slow, please-make-it-stop portion of the offseason, allow me to tell you about a quest I went on. Its mission was simple: Find out which of the seven core pitches thrown in Major League Baseball is the most devastating.

This quest led me to Baseball Prospectus’ PITCHf/x leaderboards, which feature data compiled by Brooks Baseball. Once there, I…

  • Narrowed my sights to 2010-2013 so I was looking strictly at data relevant to the current low-scoring environment.
  • Set the pitch minimum to zero so I was looking at pitches thrown by the good, the bad, the mediocre and the barely used.
  • Took data for all four-seam fastballs, sinkers, cutters, curveballs, sliders, changeups and splitters and copied the figures into Excel.
  • Ignored screwballs and knuckleballs, because only a few pitchers throw those two pitches and there aren’t enough of them to form a big enough sample size.

Now, before we go any further, two things must be acknowledged.

  1. Pitch classifications are tricky. Some four-seamers look like cutters. Some curveballs look like sliders. Some changeups look like splitters. Some changeups are splitters (spoiler: keep this in mind).
  2. It looks like the BP leaderboards don’t feature as many pitches as they should. If there’s an explanation for that, I don’t know what it is.

As such, it’s fair for the data I ended up with to be characterized as less than 100 percent conclusive. But seeing as how it was still data from two very reliable resources, and there was a lot of it, I’d put its conclusiveness somewhere in the 90-percent range. Good enough.

It’s on that note that, finally, I present to you this big board full of numbers, arranged by lowest batting average against for the sake of having a clear starting point:

Note: The figures for Swing Rate, Whiff/Swing and GB/FB represent the average of all the individual rates. Not exactly a scientific method but one that works well enough given the largeness of the sample sizes.

About what you’d expect, right? The three fastballs and changeups have their uses, but the really eye-popping numbers belong to sliders, splitters and curveballs. Some of that is due to them typically being two-strike pitches, but these are also the pitches that have the deadliest movement. They would show as the hardest to hit in a study like this one. Duh.

But you’ll notice I highlighted splitters. Look at the numbers for those and you’ll see that over the last four seasons, they’ve been:

  • Extremely hard to lay off.
  • Almost as hard to make contact with as sliders.
  • Almost as hard to hit in the air as sinkers.
  • Just as hard to hit, in general, as curveballs.

The only thing better than a swing-and-miss pitch is a swing-and-miss pitch batters can’t lay off, and the only thing better than one of those is one that hitters can’t elevate when they do make contact.

Sounds like the ultimate pitch to me, and the splitter is the pitch that matches that description the best.

If you’re looking for an excuse to nitpick, I’ll give you one: Included in the splitter data are split-changeups. Tim Lincecum throws one. So does Alex Cobb. And Danny Salazar. If you’re so inclined, maybe you’d label hybrid pitches like they’re changeups before you’d label them splitters.

But me? I’m not inclined to do that. Split-changes act more like splitters than changeups. They tend to not only have more velocity, but also that sharp, late and lethal downward action that fools hitters. Just like with regular splitters, the idea with split-changes is to trick the hitter into thinking he’s getting a fastball until—Trololol!—he’s not.

If you watch enough baseball, you’re probably familiar with this concept. If you don’t, well, perhaps you require an illustration.

That can be arranged.

Because he’s saved, according to FanGraphs, more runs above average with his splitter than any other qualified pitcher in our 2010-2013 window, we’re going to use Mariners right-hander Hisashi Iwakuma as an example. He has a darn good splitter, and he knows how to use it.

[Side note: Because it must be said, yes, Koji Uehara would have made for an outstanding example as well. Isn’t that right, Matt Carpenter?]

Consider how Iwakuma used his split at the 0:19 mark of this video, which shows him striking out Chris Herrmann in the third inning of a July 25 game against the Twins:

The sheer movement of that splitter was a work of art. But just as important to the total work of art Iwakuma performed with it is the pitch that came before it.

Per Brooks Baseball, the splitter Herrmann whiffed on was the fifth pitch of the at-bat. The fourth pitch was a four-seamer down the middle that Herrmann fouled off. While I don’t have video of that pitch, I was able to pluck a couple of stills from the Root Sports telecast using MLB.TV.

Here’s a side-by-side view that shows the location of Iwakuma’s fourth-pitch heater when Herrmann was geared up to swing next to where it was as it was entering the hitting zone:

When he had his front toe down, Herrmann was looking at a fastball that was headed middle-in. Since that’s where it ended up, here’s thinking Herrmann wasn’t pleased about missing it.

A few moments later, the fifth pitch of the at-bat came Herrmann’s way. This is a side-by-side comparison of where it was when he readied himself to swing in relation to the previous pitch:

Herrmann was looking at a pitch that wasn’t ticketed for the exact same spot as the previous pitch, but it was pretty close. If anything, the fifth pitch must have looked like a better pitch to hit given that it was headed a little more low and inside. For lefty hitters, that’s the happy-fun-times zone.

Of course, we know what happened. It turned out the fifth pitch was a splitter. It did what splitters do, diving down toward the ground and safely out of the way of Herrmann’s bat.

Now, you can go back to that Brooks Baseball link and see from the fifth pitch’s ultimate location that it ended up over the plate in the same general area as the previous pitch, except a lot lower. Or you could just look at this:

That green dot is where the fourth-pitch fastball was as it was entering the hitting zone. That red dot is where the fifth-pitch splitter was when Herrmann swung and missed.

That’s the entire concept of the splitter in a nutshell. Its deception act is a simple one: Look like a fastball for a little while, and then drop off the table. If a pitcher has a good splitter, all he needs to make it work is solid fastball command and an elementary understanding of sequencing.

Simple as that. But by now, maybe you’re more focused on the obvious question:

If splitters are so great, why aren’t there more of them?

That question is one the Associated Press was asking in 2011, with the big reveal being that the splitter had developed a bad reputation. Thanks in part to injuries suffered by notable splitter merchants like Bryan Harvey, Rod Beck and John Smoltz, the splitter came to be known as a dangerous pitch.

“You can just take your fingers and the more you put them apart, the more you put stress on the elbow,” said Minnesota Twins pitching coach Rick Anderson, referring to the splitter’s unique grip. “It’s a pitch we really try to shy off of.”

Said Angels manager Mike Scioscia: “I think there is a correlation between some stresses put on the arms—some guys have had elbow problems, forearm problems, shoulder problems—and that pitch.”

At the time, the Twins and Angels weren’t the only clubs that had it out for the splitter. The Giants, Reds, Padres and Rays were also cited as teams that discouraged their young pitchers from throwing splitters.

Whether there’s any truth to the idea that splitters put pitchers at greater risk of injury, however, is up for debate.

In a 2008 interview with Baseball Prospectus, pitching expert Doug Thorburn said, “I haven’t come across any research that found a convincing link between a split-finger fastball and a specific arm injury, and I would put this in the category of unproven conventional wisdom.”

That tends to be the case when it comes to theories about this or that leading to pitcher injuries. And in this case, what it means is that one of the reasons why clubs discourage splitters might be bogus.

Another reason, meanwhile, fairly boggles the mind.

Here’s how Rays manager Joe Maddon put it: “It’s not just about them getting hurt. They’ll never develop their other pitches because they’ll always get guys out with that pitch.”

Think about that second sentence for a moment. For that matter, go ahead and translate it.

It’s not just that splitters are good. It’s that they’re too good.

The eye test supports the notion. So do the numbers. And since it hasn’t actually been proved that the splitter is a dangerous pitch, well, maybe it’s time it made a comeback.

Unless, of course, mankind gets to that ultimate unhittable pitch first.


Note: Stats courtesy of Baseball Prospectus and Brooks Baseball unless otherwise noted/linked.


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