Keston Hiura’s reverse splits are not a fluke

Keston Hiura has not lived up to the expectations levied on him from his time as the Brewers’ top hitting prospect. Swing and miss issues have prevented him from becoming the balanced hitter that scouts hoped he could be.

At the surface level, Hiura appears to be bouncing back from the struggles he has encountered since his strong rookie season. After hitting his fourth home run of the season on Friday night, he is now slashing .250/.350/.481 for an excellent 135 wRC+.

However, there is plenty of reason to doubt that he has truly figured things out. Yes, Hiura is hitting the snot out of the baseball—when he puts it in play, which is still not very often. Even after downsizing his leg kick and switching to a shorter load, Hiura has still been unable to fix his contact issues. He is still striking out over 40% of the time.

Hiura’s swinging strike and contact rates have improved slightly from last season, but they remain distant from his 2019 levels, which were poor to begin with. Instead, he has “improved” to his 2020 levels.

FanGraphs

A perplexing element of Hiura’s struggles is his reverse platoon split. Most right-handed hitters perform best against left-handed pitching. Hiura has always struggled against them, even during his successful debut campaign. He mashed to the tune of a 1.021 OPS against right-handers but managed just a .673 mark against southpaws.

The emphasis on his splits subsided when he struggled mightily against all kinds of pitching in 2020 and 2021. However, this season, Hiura has hit all four of his home runs against right-handers and managed just four hits (all singles) against left-handers.

The sample size is too small for the splits from this season to mean much, but the results so far have led some observers back to Hiura’s career splits: an .847 OPS against same-handed hurlers and a .577 against the opposite side.

One would assume that this is due to Hiura struggling against left-handed changeups or back-foot breaking balls. Unsurprisingly, southpaws have thrown far more changeups to Hiura than right-handers have, and he has never performed especially well against them.

However, what jumps out the most in Hiura’s splits is how he fares against fastballs. He has always swung through too many heaters, whiffing on an alarming 37% of his swings against right-handed fastballs. That number gets even worse against left-handers, increasing slightly to 39%.

In his rookie season, Hiura whiffed more against right-handed fastballs (32%) than left-handed ones (27%). That changed dramatically in 2020, as he whiffed on 45% of his cuts against left-handed fastballs. In 2021, it jumped to 51%. This season, the split has evened out more (33% against right-handers, 35% against left-handers), but the whiff numbers remain too high.

What changed since 2019? Some of it has to do with Hiura’s swing-and-miss problem worsening, but it also involves some adjustments on the mound. Here is where southpaws threw fastballs against Hiura during his rookie season:

Baseball Savant

Here is where they have thrown their fastballs in the following years:

Baseball Savant

When Hiura debuted, left-handers already knew where they wanted to pitch him with fastballs. The first location was down and in to jam him and induce weak contact. The other was anywhere up in the zone for whiffs. Once it became apparent that most pitchers could get Hiura to whiff frequently, fastballs up-and-in became the go-to location.

This approach has been highly successful because it keeps the ball away from Hiura’s hot zones. He has always done the most damage on pitches that are no higher than the belt and over the middle or the outer third of the plate.

BrooksBaseball

This should not come as much of a surprise. Hiura’s strength has always been driving the ball to the opposite field, and that is easiest to do on outer half pitches. As a rookie, he went to right field (29.3%) just as often as he did to left (30.3%). This also made it easy for opponents to devise a strategy for facing him.

As a pitcher, keeping the ball up and avoiding the outer half of the plate against Hiura is a great strategy for success. Anyone who can execute a fastball above the belt to him essentially has favorable odds of inducing a whiff.

BrooksBaseball

Hiura cannot hit left-handed pitching because he cannot hit their fastballs. This is because they excel at pounding the areas of the strike zone where he cannot do damage. Hiura hasn’t proven that he can consistently square up inside fastballs, and he struggles mightily to make contact with elevated ones.

Fastballs make up 60% of the pitches Hiura sees from these left-handers. By mixing in some offspeed pitches to mess with his timing, they can make him look like a complete mess.

While Hiura has also struggled mightily against right-handers since 2019, his OPS against them has ranged from 30 to 350 points higher in each season of his career. For whatever reason, they haven’t attacked the same zones as consistently as southpaws have.

Baseball Savant

Left-handers prey on Hiura’s weaknesses. Until he can make better contact against inside and elevated fastballs, his reverse platoon split will not level out. While his career numbers against right-handers appear solid, much of that is inflated by his rookie performance, and his early success against them this year is not sustainable with his current contact numbers.

2022 is a make-or-break year for Keston Hiura. To remain in Milwaukee’s plans beyond this season, he must prove that he can reduce his swings and misses enough to succeed against big-league pitching—from both sides of the mound.

Statistics courtesy of FanGraphs, Baseball Savant, and BrooksBaseball.