Matt Wallner hits baseballs very hard. He hit a pitch 116.4 mph last season, good for 97th percentile. Wallner also swings and misses a lot, especially at pitches in the zone. His 73.1% zone contact rate (Z-Con%) last season was third-worst in the MLB among players with at least 200 plate appearances.
Wallner’s extreme approach has flaws, but he could become the best power hitter for the Minnesota Twins since Nelson Cruz.
Striking out isn’t fun. There’s no consolation prize for being close to connecting with a pitch, making high strikeout power hitters risk-reward propositions in baseball lineups.
Lineups completely devoid of power but more disciplined at the plate may lack the punch necessary to score runs. But lineups full of powerful strikeout-prone players could struggle to string together hits at the right time to score. It’s all about balance, and the Twins have Wallner to complement their on-base hitters like Edouard Julien and Carlos Correa.
In some ways, Wallner is a balanced hitter. He doesn’t whiff at bad pitches, tailoring his swing perfectly for pitches in the bottom two-thirds of the zone. But Wallner misses plenty of pitches in the zone, as evidenced by his poor Z-Con%, which measures the percentage of swings a batter doesn’t whiff on when the pitch is in the zone. Wallner still excels in weighted on-base average (wOBA), though, the most important statistic for sluggers, if not all hitters in general.
The visualization below, courtesy of BaseballSavant and Statcast data, shows Wallner’s whiff rates against four-seamers broken up into zones, followed by a visualization depicting the same thing but as a league average:
Pitchers seem to have discovered Wallner’s weak point up in the zone. His upper-cut swing is almost entirely to blame for this hole. His bat path is rarely on plane with a high fastball’s pitch trajectory. Therefore, he needs to time his swing to make contact perfectly. You can see that live in the video below:
But despite Wallner’s propensity to whiff on high fastballs, he dominated them. Wallner may miss often, but he always made excellent contact:
wOBA assesses how a player gets on base and how useful it is for scoring runs. By that metric, Wallner was terrific. There’s an odd zone up and inside where he hit for 0.000 wOBA. However, that can likely be attributed to a small sample size of just 206 pitches in the upper five zones and just 20 up and inside.
Wallner’s ability to hit high fastballs well – even while whiffing on many, if not most, of them – will ensure he’s a great hitter. He has all the necessary tools to be a great slugger.
He has a keen eye for the strike zone and regularly hits for more bases than expected. PitcherList’s Decision Value metric models how many runs a hitter adds in their decision to swing or take a pitch. Using Decision Value, we can see his growth as a hitter over 2023 as the season progressed:
Wallner swung at pitches that hitters produced the most runs on and took pitches that hitters did not produce many runs on. His Swing Decision score was 130, or 30% better than average. Wallner built that on his 129 Strike Zone Judgment (29% better than average) and 138 Power (38% better than average).
He often correctly took pitches outside the zone and swung at pitches inside it. Wallner also did so while hitting for about 0.2 more bases on his batted balls than the average hitter on hits from the same location in the zone. Most importantly, he continues to make good decisions with two strikes:
I’m intentionally emphasizing Wallner’s decision-making. Sluggers can’t afford to swing freely, or at least those who want to have any semblance of consistency can’t afford to swing freely. It’s a somewhat similar argument to Stuff+ with pitchers.
Stuff+ is “stickier” year-to-year than Command+, meaning pitchers maintain similar Stuff+ marks from year to year. Therefore, pitchers with good stuff appear more reliable to project.
There has yet to be any research on Decision Value stickiness. However, I reason that hitters with quality decision-making are more consistent than those who don’t. They may lose contact and power over time, but quality decision-making might not.
Beyond Wallner’s curated approach, he improved at making decisions against left-handed pitchers:
It’s another small sample, but Wallner made substantial progress. He’s solidifying himself as an impact hitter who Rocco Baldelli won’t need to platoon.
Wallner knows what he wants to hit, and he can turn what he wants to hit into extra bases. He whiffs often, including at pitches in the strike zone, but it’s not for a lack of ability. Wallner has three strikes to work with, and his eye allows him to keep plate appearances alive. He’s not a free swinger like some other sluggers. Wallner plays with a curated approach that ensures a long, fruitful career. Perhaps he can avoid a sophomore slump if he continues to combat high whiff rates on high fastballs with immense power.
