Kevin Gausman's splitter has been one of the best pitches in baseball

A successful major-league pitcher needs a pitch he can trust to get a swing and miss when he needs it.

Kevin Gausman has one of those that hasn't just been reliable — it's been one of the best pitches in baseball.

Kevin Gausman's splitter has been one of the best pitches in baseball

Aside from his fastball, the split-finger (also known as the splitter) is Gausman's second-most used pitch. The Blue Jays righty throws the splitter about 32% of the time, according to Baseball Savant, making his association with the pitch so ubiquitous that it spawned a hashtag on X: #DaSpwitter.

For those unfamiliar with the splitter, it is an offspeed pitch, despite occasionally being referred to as a "split-finger fastball." It looks like a fastball when it leaves the pitcher's hand, but it's slower than a fastball and drops right before it reaches the plate.

In his own words, Gausman throws the splitter with the ball between his index and middle fingers, with the ball pushing off the middle finger. That causes the ball to drop and spin like a breaking ball from a left-handed pitcher. To a right-handed hitter, the pitch is coming down and in, while a left-handed hitter would see it low and away.

Because of the effectiveness of the pitch, Gausman has seen more success with the splitter than anybody else in baseball since the start of the Statcast era in 2015.

Since then, the two-time All-Star has garnered 1,712 swinging strikes (swing and misses, foul balls, etc.) with the pitch according to Statcast. That is significantly more than any other pitcher during the same time period, with free agent hurler Hector Neris coming in second with 1,013 swinging strikes.

The Blue Jays don't have a ton of starting pitching depth, so having reliable starters like Gausman go deep into a game is a must. To do that, pitchers have to get outs effectively, which is exactly what Guasman has done thanks to his splitter.

Gausman held hitters to a 28.8% hard-hit rate on his splitter last year to go along with a 31.5% strikeout rate and 33.5 whiff (swing-and-miss) rate. Batters hit just .169 on the pitch.

In 2023 (Gausman's last All-Star season), he held hitters to a 29.3% hard-hit rate on the pitch to go along with a 41.9% strikeout rate and a 43.2% whiff rate. Batters hit just .201 on the pitch.

Gausman is valuable to Toronto, as evidenced by the fact that he's made 31 starts in every season since he joined Toronto in 2022.

He's also off to a strong start to this season, as he has a 2.49 ERA and 0.71 WHIP in 25 1/3 innings.

But there's still some concern under the hood.

This year, batters have a 34.6% hard-hit rate against the pitch. While batters are hitting just.129 against the pitch, he only has a 18.2% strikeout rate and a 19% whiff rate with the pitch. He also only has 20 strikeouts this year.

Those numbers are way below his career norms.

It may be too early to get worked up about the drop in those numbers, and Gausman's track record suggests he'll figure it out.

Last season for example, Gausman didn't get off to a good start before finishing the season strong. For the Blue Jays to make a deep October run, they'll need Gausman at his best as the season goes on.

And while his numbers this year aren't as strong as they've been before, his strong track record is a reminder that it's far too early to panic.