Jackson Merrill Hasn't Found Love in the Heart of the Zone

[N.B. Lindberg]

The San Diego Padres improbably find themselves at 31-22 and keeping pace with the reigning champions in the National League West. It’s not that the Padres being one of the best teams in the league is wholly surprising; it is how they’ve gotten there that is. At the beginning of the season, if someone had told you that the Padres were challenging the Dodgers for the division title, your first thought would have likely been that Fernando Tatis Jr., Manny Machado, and Jackson Merrill had played at an MVP level, but you’d be wrong. 

The Padres have gotten here despite their star trio. Machado has a wRC+ of 76, Tatis clocks in at 77, and Merrill sits at a lowly 74. Thankfully, their defensive abilities have prevented them from being complete negatives, but that trio's underperformance is the primary reason the Padres own the league’s 27th-ranked offense by wRC+ at 90. While Tatis’ continued home run drought, despite excellent hard hit rates, is well chronicled, as is Machado’s perplexing brand of flaccid patience, Merrill’s struggles have flown a bit under the radar.

Jackson Merrill, Future Star

Bursting onto the scene as a 21-year-old rookie, Merrill looked like a future star and potential perennial MVP candidate. His 130 wRC+ as a rookie, while performing admirably in center field, a position he had never played as a prospect, led to an incredible 5.3 fWAR season, and saw him finish second in Rookie of the Year voting to Paul Skenes. It was enough to get the Padres to offer him a nine-year, $135 million extension that no one batted an eye at.

Early in his career, the game plan for Merrill was simple. In possession of an incredibly variable swing, he could square the ball up anywhere in the zone for doubles damage. His blend of contact volume with above-average pop formed the foundation of an incredibly enticing profile. If either his plate discipline or power trended up, two traits that usually improve as a hitter matures, he would instantly become one of the game’s elite hitters, but after a slight backslide in his second season, he has completely fallen off in year three. 

So, what’s exactly befuddling such a talented hitter that he could go from being an All-Star as a rookie to one of the league’s worst non-catcher hitters? Well, he isn’t getting results in the heart of the zone. 

Finding Love in the Heart of the Zone

The dirty secret of hitting is that the pitcher is in almost complete control. The vast majority of extra-base damage is done on pitches the pitcher would like back, and no one tries to throw balls. Even a mediocre fastball, if well executed, is going to give the best hitter fits, which is why the best hitters excel at taking advantage of mistakes, either through slugging pitches down the middle or spitting on pitches off the plate. 

Merrill isn’t blessed with an elite batting eye, but early in his career, it didn’t matter. He offered at pitches outside of the zone infrequently enough that it didn’t detract from his ability to square up balls in the zone. The trade-off as a hitter he was making made sense. Yes, he’d swing at some bad pitches, but he’d rarely fail to offer at ones he could drive. The result was a lower walk and strikeout rate, but a higher batting average and slugging percentage. Unfortunately, the entire operation has gone backwards this season. 

Through 50 games and more than 200 plate appearances, Merrill’s contact ability has continued to erode, and he’s offering at pitches outside of the zone more than ever. However, that isn’t what’s really troubling him. Plenty of hitters can succeed with this approach as long as they punish the mistakes in the heart of the zone. The problem is that Merrill hasn’t done enough with those crushable mistakes. 

Compared to 2025, Merrill has seen a concerning drop in his production in the dead center of the strike zone. 

*Stats as of the week of May 25

It’s still early, but Merrill is whiffing more and hitting for a worse average and slugging percentage on pitches down the middle. If he were still using the same approach as his rookie season, his overall production would probably still be fine, but because his approach has shifted to take advantage of those exact pitches at the cost of plate coverage, it’s a serious problem. 

Now, it would be fine if Merrill’s plate discipline and in-zone contact figures declined if it came with a corresponding bump in production right down the middle, but right now, everything is coming up snake eyes. However, there is some good news.

Process Over Results in the Heart of the Zone 

Whether or not you think Merrill changing his approach from being a plate coverage monster to a home run-seeking slugger is a positive development, it appears to be the choice he has made. The good news is that while his surface numbers in the heart of the plate have declined, the underlying batted ball data suggest he has been incredibly unlucky. 

 

By and large, Merrill’s new approach has been working from a process standpoint. He has sacrificed his ability to cover the entire plate to improve his contact in the heart of the zone. However, one of the problems when you make this decision is that you’re at greater mercy of batted ball luck and the unknowable location of each pitch. 

A two-percent drop in pitches down the middle doesn’t seem like much, but for a hitter it’s massive. Merrill has swung at 92% of pitches down the middle this season and made contact at an 84% clip. This season, he has faced 797 pitches. At an 8% dead center rate, that’d equal 63.76 total pitches, but at 6%, it drops to 47.82. That’s 15.94, let’s say 16, fewer pitches where Merrill would swing 92% of the time, equaling 14.72 more swings and 12.36 more times where he makes contact. Considering his expected slugging is 0.943, that’s an incredible loss in potential production. 

In all likelihood, Merrill will see his metrics regress towards his expected stats in the heart of the zone, and it’ll pull his offensive production out of the red. While we can expect better days for Merrill ahead, it’s another matter if this evolution was the right one to take. He’s walking and striking out more because pitchers are throwing him fewer strikes, even though he’s chasing more than ever. On pitches not down the middle, his underlying production has mostly declined. While you can get the most bang for your buck on dead-red fastballs, Merrill’s superpower was his ability to get plenty of bang on pitches throughout the zone. 

This new approach will probably lead to Merrill being far streakier, as we’ve seen in the bad way, to start the season. Now, it’s not like Merrill has to abandon his new approach for it to be worthwhile, but he does need to refine it. If he can rein in the chase and continue to aggressively hunt middle-middle pitches, he’ll be fine. But if the chase is the cost of doing business, he might be better off covering the whole plate. 

The good news for the Padres is that they’re well above .500 and better days are likely ahead for their youngest star. His new approach might not be optimal long-term, but he has executed it far better than his current production would suggest. As the summer starts to heat up and he gets an unusually high number of middle-middle pitches, don’t be surprised if he goes on a surge, but also don’t be surprised when he comes crashing back to Earth. Merrill is still a good hitter, but he is fundamentally a different one than the star we knew.

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