Anatomy of a home run: Jarred Kelenic’s improved approach against Ohtani’s splitter

Jarred Kelenic’s game-tying home run yesterday gave him the highest WPA (.222) for any Mariners batter in the contest, even more than Mitch Haniger’s go-ahead single or Jake Fraley’s game-clinching, bases-clearing double. Kelenic punishing a hanging slider from Ohtani was obviously deeply cathartic to witness, but it’s what he did against Ohtani’s splitter that deserves more accolades.

It’s clearly no secret that the book on how to attack Jarred Kelenic is with the off-speed. Kelenic is slugging close to .500 on four-seamers, which probably explains why he sees them just 30% of the time. Mostly it’s been a steady diet of sliders (18%), curveballs (17%), and changeups (13%). Not a ton of pitchers throw a splitter—they account for just about 1.5% of all pitches thrown—but Jarred has seen more than twice that average, almost 4%. And when he has seen splitters, things have not gone well: he’s whiffed at them more than any other pitch he’s seen (46.2%). Kelenic struggles to pick up the splitter much like he struggles with sliders low in the zone, going fishing after them; his run value of -6 on sliders is the lowest of all pitches he’s seen.

Prior to yesterday’s game, Kelenic’s last matchup with Ohtani was on June 4, a 2-3 loss for the Mariners. Jarred had two plate appearances against Ohtani: one that ended in a groundout (96 MPH EV) on a fastball, and one on the splitter for a strikeout, burying the pitch right at the bottom of the zone for Jarred to swing over:

Ohtani also threw Kelenic one curveball he didn’t land for a strike, another splitter in the dirt Jarred laid off of, and four fastballs. One missed badly and Kelenic took it for a ball, but the rest were in the zone; Kelenic made contact on all of them.

In their second matchup, the plan was obvious: avoid the fastball and attack Kelenic on the two pitches he’s weakest on, the slider and splitter. The Mariners attracted a lot of flack on Twitter from Ohtani fans for pitching around Ohtani in the opening game of this series, birthing the amusing hashtag #ChickenMariners, but Ohtani didn’t seem too interested in challenging Kelenic with his plus fastball, even as he was sitting an easy 97-98 with it; Kelenic didn’t see a single fastball from Ohtani in this contest.

In his first at-bat, Ohtani went after Kelenic with three straight sliders, getting ahead in the count 1-2 before dialing up the splitter. However, Ohtani’s location wasn’t buried like Cobb’s was, and even though Kelenic still chased the pitch off the plate, he was able to make contact with it for a groundout:

In the fifth, Kelenic jumped on Ohtani’s first pitch, ambushing the splitter:

This split doesn’t have a ton of great break or movement, and Kelenic is able to cut it off before it gets too far down. Batters are hitting just .079 on Ohtani’s splitter this year, but Kelenic makes hitting it look easy here.

Joe Maddon’s decision to leave Ohtani in for a seventh inning, despite his mounting pitch count, is baffling on many levels, but his unwillingness to substitute in a different pitcher to face Kelenic—hoping that he could wring another at-bat from Ohtani in the bottom of the 7th, one assumes—is perhaps the most baffling. Opposing managers have been quick with the hook when Kelenic has come up to bat in later innings this season; he has about 150 plate appearances against relievers and only about fifty more than that against starters. Part of the reason opposing managers substitute so often against Kelenic is to attempt a matchup advantage; Kelenic loses 200 points off his slugging percentage against lefties, and a hundred points off his batting average against relievers, and lefty relievers have been especially brutal on him, as we saw in the series against the Astros when Kelenic was battered by a seemingly unending barrage of lefties, relievers, and lefty relievers, leading to a season strikeout percentage against Houston of 53%.

Another reason opposing managers substitute against Kelenic later in games, though, is he gets markedly better the more chances he has to see a pitcher: his slugging percentage rises from .300 the first time he sees a pitcher, to .500 the second, to .700 the third. All this to say: the fact that Maddon didn’t bring in another pitcher to face Kelenic, hoping to keep Ohtani in and win the game, likely in fact lost the Angels the game.

I broke this down in the recap, but with Kelenic ambushing the splitter first pitch in his last at-bat, Ohtani didn’t want to throw that; he was still unwilling to throw Kelenic a fastball. That left the slider, and Jarred had no problem spitting on Ohtani’s first offering, a hanging slider well out of the zone. Ohtani went back to the slider for a called strike two, even as the pitch was pretty plum, location-wise, suggesting Jarred was maybe expecting the fastball. It certainly looks like he’s gearing up for it with the leg kick here:

Pitching coaches preach the importance of winning the 1-1 count; that’s often when a pitcher will throw their best pitch, trying to get ahead in the count and be able to expand the zone from there. Ohtani’s best pitch, by a significant margin, is the splitter. Instead, he hung a slider, and Jarred did not miss it.

I’m a little sad that video doesn’t include the Angels announcers lavishing praise on Ohtani for his superb command, but you’ll just have to trust me that literally right before this was hit they were talking about how good Ohtani’s splitter is.

Kelenic won’t win these kinds of battles every time. A series of different choices here—bringing in a reliever/not leaving Ohtani in, a different pitch selection, better location by Ohtani on both the splitter and the slider, Jarred laying off that pitch for a called strike two—could result in different outcomes. But it’s encouraging to see him be able to weaponize other teams’ unwillingness to throw him fastballs instead of getting stung by that, and it’s yet another feather in the cap for Seattle’s young rookie in a September that’s been full of much more promise than peril.