Mize's splitter becoming a groundout pitch

DETROIT -- The splitter has been Casey Mize’s marquee pitch since he became a star at Auburn, where it was a strikeout pitch for him.

While Mize’s jump in fastball velocity has been an important part of his encouraging start -- ranking him in the 87th percentile among Major League pitchers entering his start Friday against the Royals -- his splitter has arguably been just as important. It hasn’t been the strikeout pitch it was in college, but it has become a contact pitch for him to get groundouts.

Mize’s splitter drew some nasty swings and misses in his first couple starts in the Majors after the Tigers called him up last August. Eventually, hitters saw it either in person or on video and adjusted. He still finished with a 28% swing-and-miss rate with it, according to Statcast, but opponents batted .313 off of it with an average exit velocity of 90.1 mph, harder than off any other pitch, except his curveball.

Through three starts this season, the whiff rate on Mize’s splitter is down about half, to 14.3%, but the contact hitters are making off it isn’t nearly as strong. The 85.4 mph average exit velocity is a drop of nearly 5 mph. Opponents are batting .214 (3-for-14) off of it, with all three hits being singles. The average launch angle is minus-12 degrees, meaning hitters are pounding it into the ground.

The shift reflects in his overall game. Mize’s ground-ball rate has jumped from 39.3% last season to 59.2% this year, while his line-drive rate has dropped from 33.7% to 14.3%. His barrel rate has also dropped, from 13.5% to 10.2%.

Those numbers could regress; Statcast expects a .301 average off Mize’s splitter based on contact, hit placement and exit velocity. Still, it’s an interesting transition.

“The ground-ball percentage I think is just coming from throwing more splitters for strikes,” Mize said Thursday morning. “And I think being in the zone with that a little bit more has allowed for weak contact. Slider, the same way. And then pitching inside with the four-seamer, and even occasionally with the two-seamer, to get some weak contact and put the ball on the ground is probably the reason you’re getting the results.”

Mize is throwing his splitter slightly harder, from an average of 86 mph in 2020 to 87.8 mph so far in '21. The spin rate is the same at 1,260 rpm.

Likewise, the horizonal movement on Mize’s splitter is the same, but the vertical movement is down from 38.1 inches of break last year to 33.8 inches this season.

Quick hits
• Miguel Cabrera took batting practice on the field Thursday morning as he works his way back from a left biceps strain that landed him on the 10-day injured list on April 11. Hinch has said Cabrera could return at some point this weekend against the Royals.

• Nomar Mazara has taken his rehab to the Tigers’ Spring Training facility in Lakeland, Fla., and is expected to miss at least the next seven to 10 days. Mazara suffered a left abdominal strain on a swing April 14 in Houston.