Why hitters can't lay off Gausman's splitter

May 1st, 2022

is doing his best Corbin Burnes. At the end of April, he's third in the American League with 31 strikeouts -- and he has zero walks.

The Blue Jays right-hander is still barely halfway to Burnes' record-setting 58-strikeout, no-walk start to the 2021 season, but it's worth breaking down how Gausman is doing this as he makes his first start of May.

He's throwing a pitch that's impossible to lay off.

See, Gausman isn't on this zero-walk streak because he's throwing everything in the strike zone. Far from it. His in-zone rate of 49.3% is right about league average. What's actually behind his success is this: Gausman's splitter is the best chase pitch in baseball.

Let's take a look at the starting pitchers inducing the top overall chase rates right now.

Highest chase rate induced, 2022
Min. 150 out-of-zone pitches thrown
1. Kevin Gausman: 53.2%
2. Max Fried: 40.5%
3. Walker Buehler: 37.4%
4. Joe Musgrove: 36.4%
5. (Tie) Dylan Cease: 35.4%
5. (Tie) Sean Manaea: 35.4%

Opposing hitters are chasing over half of the pitches Gausman throws outside the strike zone. The difference between him and the next-closest ace on that list is huge -- from Gausman to Fried is the same as the gap between Fried and the starter with the 67th-highest chase rate, Miles Mikolas.

And here's where all those chases are coming from:

Highest chase rate on individual pitch type, 2022
Min. 50 out-of-zone pitches thrown of that type
1. Kevin Gausman's splitter: 72.9%
2. Andrew Heaney's slider: 52.0%
3. Logan Webb's changeup: 50.7%
4. Clayton Kershaw's slider: 50.0%
5. Shane Bieber's slider: 49.3%

Nearly three out of every four splitters Gausman throws out of the strike zone, the hitter swings anyway. This time, the gap between No. 1 Gausman and No. 2 Heaney is the same as the gap between Heaney and No. 35 Tony Gonsolin with his slider.

And it turns out, Gausman doing this for an entire calendar month is a record.

Gausman's splitter chase rate is the highest for any pitcher on any pitch type in any calendar month in the entire pitch-tracking era, which goes back to 2008.

Highest chase rate on individual pitch type in a month, since 2008
Min. 50 out-of-zone pitches thrown of that type
1. Kevin Gausman's splitter, April 2022: 72.9%
2. Randall Delgado's changeup, July 2013: 67.1%
3. Brandon Webb's changeup, May 2008: 66.7%
4. Daniel Hudson's changeup, August 2011: 65.6%
5. Ryan Madson's changeup, August 2011: 65.5%

You can also look at what Gausman is doing through the sheer volume of chase swings he's getting. Gausman leads all pitchers in both total chases (92, two more than Montas, who has an extra start on Gausman) and chases on a single pitch type.

Most chase swings induced on individual pitch type, 2022
1. Kevin Gausman's splitter: 62
2. (Tie) Carlos Rod贸n's 4-seamer: 41
2. (Tie) Pablo L贸pez's changeup: 41
4. Frankie Montas' splitter: 37
5. (Tie) Logan Webb's changeup: 36
5. (Tie) Michael Kopech's 4-seamer: 36

Gausman is more than 20 chases ahead of the pitcher who essentially replaced him in San Francisco, Rod贸n, and his overpowering fastball.

And those chases turn into strikeouts. Gausman has 22 on his splitter already, second-most on any pitch type in baseball -- after Rod贸n's four-seamer, which has 24. On 17 of those 22 K's, the hitter chased a splitter out of the strike zone. Gausman's 17 chase strikeouts on splitters are five more than any pitcher has on any other pitch type (Kershaw's slider has 12).

Here are a few more fun facts about hitters chasing Gausman's split:

  • On at-bats that have ended on a chased Gausman splitter this season, opposing hitters are 2-for-32, an .063 batting average, with the 17 chase K's
  • Hitters are whiffing on 51.6% of their swings when they chase a Gausman splitter out of the zone
  • When Gausman throws his splitter with two strikes, he's putting the hitter away for a K 37.9% of the time

Highest putaway % on individual pitch type, 2022
Min. 50 2-strike pitches thrown of that type
1. Kevin Gausman's splitter: 37.9%
2. Jes煤s Luzardo's slurve: 33.3%
3. Justin Verlander's slider: 31.5%
4. Corbin Burnes' cutter: 30.0%
5. Carlos Rod贸n's 4-seamer: 28.9%

So why can't Major League hitters lay off this pitch? Let's look at how Gausman tunnels his pitches. Gausman's splitter looks just like his fastball, and he throws them in sequence all the time.

The two pitches look alike, first of all, because Gausman throws his four-seamer and splitter on a near-identical spin axis. Their spin direction is even closer together than last year, when his fastball/splitter combo led him to a sixth-place Cy Young finish.

Second is the movement. Gausman's fastball and splitter both run the same direction to his arm side -- his four-seamer averages 11.4 inches of horizontal break, and his splitter averages 15 inches, both several inches above average.

But the splitter, which is 10 mph slower, drops almost two feet more than the fastball -- 36.2 inches compared to 13.5 inches.

Third is the pitch location. Gausman is throwing his fastball and splitter on the same vertical plane. The fastball rides up and to the arm-side at the top of the strike zone; the splitter drops off the table through the bottom of the strike zone directly below it.

The fastball and splitter are thrown the same, move the same, and come at the hitter on the same track. They can't help but chase the split. And as long as they can't help but chase the split, Gausman is going to be an ace in Toronto.