He can make S’mores, but we’d just as readily take s’more power
So there’s this psychology study where some researchers at Stanford put a marshmallow in front of kids, and told them they had a choice: eat the marshmallow or wait 15 minutes and, if the marshmallow was uneaten, get another marshmallow. It was meant to assess the kids ability to delay gratification. It’s one of the better known psychological studies, and it’s a lot more pleasant to think about than that other famous psych study that came out of Stanford around the same time (imagine the conversations in the student lounge between the research assistants doling out marshmallows and the ones that had to set up a fake prison).
Anyway, as a team, the Phillies wouldn’t get that second marshmallow.
Not being a particularly patient bunch, the 2025 Phillies are swinging at the first pitch 35.2% of the time. Only the Astros take a hack at more inaugural offerings. This year’s Fightin Phils are trending towards less patience as a team, though only slightly: last year’s unit swung at 34.5% of first pitches, and the 2023 squad swung at 32.4%. Their haste to get their lumber moving is nothing new.
But that topline number is hiding some interesting changes at the individual level.
Quite a few Phillies have changed their approach to first pitches. It’s just that those changes are largely canceling each other out at the team level. Johan Rojas and Brandon Marsh are getting a lot more aggressive. Bryson Stott, already known for his patience, is chilling out even more.
It’s J.T. Realmuto who might have the most interesting changes though. His decrease in 1st pitch swing rate of 5.6% is substantial, though it looks a little scrawny when Stott’s is nearly twice as large. A close look at the other numbers relating to his aggression don’t seem to indicate much of a change. His overall swing rate is down two percentage points to 48.5%; that’s notable but not huge. His chase rate has changed by a minuscule 0.1. So what’s the big deal?
About a year and a half ago, Robert Orr of Baseball Prospectus introduced a new statistic known as SElective AGgression Engagement Rate, or SEAGER (yes, after Corey), which combines a batter’s willingness to swing at good pitches to hit and their willingness to let bad ones pass by into a single statistic. You can (and should!) read more about it in the original article, but the general idea is that the higher one’s SEAGER, the better they are at practicing selective aggression. As some examples of how this works: Kyle Schwarber ranks extremely highly in SEAGER because he’s vanishingly unlikely to swing at bad pitches, and above average at avoiding letting hittable balls go by. Bryce Harper also ranks very highly in SEAGER because few players are less inclined to say no to a hittable ball. (If you want to see how everyone else stacks up, the leaderboards are here)
In 2024, Realmuto’s SEAGER was 11.2. Don’t pay so much attention to that raw number, but rather consider that this put him in the 35th percentile league-wide. In other words, he was below average at being selectively aggressive. He let 36.4% of hittable pitches pass him by (45th percentile) and ranked in the 33rd percentile for selectivity (meaning not swinging at the stuff you shouldn’t swing at).
In 2025, Realmuto’s SEAGER is 15.3, which places him in the 72nd percentile. He’s gone from being well below average in selective aggression to being well above average. He’s letting fewer hittable pitches pass him (34.7%), moving into the 74th percentile in that regard. And he’s swinging at fewer bad pitches too, moving all the way up to the 58th percentile in selectivity.
So we have a J.T. Realmuto who’s more patient than before, one who’s more willing to let the bad pitches go along their merry way, but less willing to let the hittable ones off with a warning. That all sounds like good stuff. He’s not as selective as Schwarber or as aggressive as Harper, but he’s taking a better approach at the plate.
It’s not showing up in his overall batting numbers, though.
This season, Realmuto is slashing .234/.301/.359. All three elements are down from last year’s .266/.322/.429, and that .660 OPS isn’t going to be adding another Silver Slugger to his trophy case. So what gives?
Part of it is that he’s been a tad unlucky. His xBA is .262 vs. the actual of .234, and his xSLG is .424 vs. the actual of .301. But it’s not all luck. See, there’s two parts of hitting: your swing decisions, and your actual swing. Realmuto’s seen positive change in the former. The latter is a different story.
If we look at Realmuto’s swing data, we can see he’s changed it slightly. He’s swinging the bat slightly slower (72.5 MPH, down from 73.2 last year), and his fast swing rate (that’s the % of swings that reach 75 MPH+) is down by over 5%. He’s making contact a little closer to the front of the plate, and his swing is a bit flatter. None of this seems huge, but it may be having some effect.
Here’s Realmuto’s batting average by zone of the plate in 2024:
and 2025:
Here’s Realmuto’s SLG by zone of the plate in 2024:
And here’s 2025:
Realmuto is doing much less damage overall, and notably in the parts of the zone best suited to doing damage. Maybe that’s because of the changes in his swing. Maybe his more selective approach at the plate has made him more hesitant (hence the slower bat speed), and thus less able to to damage when he swings. Either way, he’s making better decisions about which pitches to swing at, but not inflicting as much pain on the ones he does swing at.
At the moment, J.T. is getting that marshmallow, but it’s not tasting so sweet. He’ll have to find a way to maintain his improvement in selective aggression while finding a way to do more damage when he swings. That may take a while, or it may not. It’s hard to wait, sure. We’d rather see it happen now. But that’s what delayed gratification is all about.