There is an issue. Is it fixable?
Sometimes when we look at the teams we follow, we can harp on those that are not performing. People expect, nay demand, excellence from the players and when it doesn’t occur, wrath will follow. It is a lot easier to continue to expound on those issues when they are happening to players that we were down on in the first place. It helps confirm the biases that were in the back of our minds already. It’s when the issues are happening with the stars of the team, the ones that have the more glowing baseball card backs where we can get almost defensive by nature. No one wants to criticize the star, even if that criticism is warranted.
Of course, often times, that star player is the most critical of himself. He knows the weight that is on his shoulders as far as expectations go and when those expectations are not met, there is no bigger critic than the player who is struggling. Turning to the Phillies, one of the stories of the season so far is that Bryce Harper just does not seem right. He has admitted in print and in interviews how much of a “grind” he has been going through, fully aware that the numbers and production are not where they are expected to be. It can be easy to simply brush them off since the track record of Harper playing well is long and robust.
Yet there is a creeping concern the team should be having about Bryce Harper. It has been growing for some time, somewhat below the radar and it looks like this season, it’s becoming more and more pronounced. It’s a seemingly fixable issue, but it’s going to need to be fixed soon.
Every hitter in the game is going to go through slumps. Baseball is a game of failure, sprinkled with success around 30-35% of the time. That success can vary in nature, but it is success nonetheless. When it comes to the failures, if they are longer stretches than those that include sustained success, it can be frustrating to watch.
Right now, we can say with relative confidence that Harper is slumping. Now, his idea of a slump is likely different than about eighty percent of the players in the game thanks to his status as an elite hitter, but it’s almost time that we stop ignoring that it is happening. In all these games to begin the 2025 season, Alec Bohm has borne the brunt of the fanbase, the rotating cast of characters in the outfield has seen pushback and even Trea Turner has taken his turn in the crosshairs of criticism. Yet somehow, outside of a few whispers here and there, Harper has gone somewhat unscathed.
We’re not here to talk about that phenomenon. Instead, we’re searching for answers as to why those struggles are occurring. Why is Harper struggling? What has been the main issue?
Scott Lauber of the Philadelphia Inquirer wrote an excellent piece last week detailing some of the struggles Harper has had. What he found was that pitchers have (wisely) changed their approach to facing Harper.
Indeed, Harper has seen the lowest percentage of pitches in the strike zone — 42.9% through Friday night — of 282 major-league hitters with at least 50 plate appearances this season. By contrast, leadoff-hitting Bryson Stott leads Phillies regulars with 55.4% of pitches in the zone…[a]nd when Harper does get a pitch over the plate, it’s often a breaking ball. Entering the weekend, he faced more curveballs — by total pitches (107) and percentage (16.4%) — than any hitter with enough at-bats to qualify for the batting title…[h]ere’s the thing: It’s working. The combination of staying out of the strike zone and coming in with mostly curveballs and sliders has diminished Harper’s production. Through Friday, he was batting .229 and slugging .403.
All of which is true, but it also misses a few piece of information. While that number has changed – he’s seen pitches in the strike zone 42.3% of the time through Monday’s game – that number is really no different than how often pitchers were putting pitches in the strike zone in 2024 (43.3%) and is actually better than how often they put pitches in the strike zone in 2023 (40.5%). In 2024, that percentage was third lowest of all qualified hitters and the two hitters ahead of him – Javier Baez and Jhonkensy Noel – had no reason to see pitches in the strike zone as they would swing at anything in the same zip code.
And those curveballs, the ones that are pointed out as being strangely out of line with his career? Harper is actually hitting them quite well (.304 BA/.462 SLG against). If they want to throw more curveballs, by all means go ahead. He’s hitting them and hitting them well.
So while yes, there have been an inordinate amount of pitches out of the strike zone this year, it’s not out of line with Harper’s career and not the real root of the problem. No, the real issue is a bit more disturbing, I’m afraid.
Baseball Savant has shown player data on pitches in the strike zone by defining all the parts that surround it and giving them names, most of them self explanatory: Heart, Shadow, Chase, and Waste. The Heart of the strike zone is pretty obvious – the spot in the zone that is completely inside of the defined strike zone of the rule book. The Shadow zone is what is on the edges and the space where umpires will vacillate what are balls and strikes. The Chase zone is where pitchers are trying to get a hitter to chase pitches and the Waste zone, well, that’s pretty easy. It’s where pitches are obviously wasted and not really close to being swung at (unless you’re Baez). Clearly, one would want to do the most damage on pitches in the Heart of the zone since they are the best ones to hit – they’re strikes and will be swung at most often. Savant will talk about different run values assigned to each pitch that enters each zone, something I’d suggest reading quickly.
This is where we start to find the information about Harper that is concerning.
A hitter of his caliber, one would expect Harper to thrive on pitches in the Heart of the zone since, again, that is where the damage is done. The data backs it up that in the past, Harper has done well there.
Seeing struggles in the Shadow zone makes sense as that’s where pitches are likely to be interpreted as a strike or ball differently by umpires and where the pitchers are trying to live. But what’s intentionally left out is 2025’s data to this point. This is where we’re getting a bit more concerned. Here are 2025’s numbers for Harper:
- Heart: -6
- Shadow: 2
- Chase: 4
- Waste: 3
Seeing a negative number on pitches in the Heart of the zone is a big issue. That means that pitches Harper should be doing his most damage on, he is having the most troubles with. It gets even more concerning when one talks about another issue: fastballs.
Over his career, Harper has been a good fastball hitter, as many elite hitters are. They’ve seen it most often and practice against it most often. But there is a trend starting to emerge with Harper and the fastball. You can see that fastballs have been steadily starting to get the better of Harper in the past few years.
However, it’s not just that it is the fastball in general that has seen a drop, it’s a fastball in a particular spot – the middle of the plate. I ran a search on pitches 94 miles per hour or more in the Heart of zone for Harper, sorted by wOBA and year, and came across a rather stunning data point: Harper is getting worse against pitches he should be hitting.
Folks, that ain’t great. If there is one spot in a hitter’s strike zone that we can reasonably assume they will find the most success, it’s pitches in this part, the Heart of the zone. Were we to start to narrow down why Harper has been struggling in 2025, it can be boiled down to one simple concept – Harper is getting beaten quite badly on fastballs in the middle of the plate. As a hitter, that just isn’t good. And judging by the percentage of fastballs thrown there and how it is creeping up a bit, pitchers are starting to throw them in the Heart more often, seeing he hasn’t been doing as well. The doomsayers will point to that and claim that the decline of Harper has begun.
Is that a fair assumption to make though?
I’d actually argue that there are several things to take solace in here. The first is that as poorly as he has performed, based on his underlying metrics, Harper should be doing much better. Here is that same data, only with xwOBA added in (what we should be expecting Harper to be doing).
You can see that Harper should be doing much better against these pitches based on things like bat speed, launch angle and the like. While there have been discrepancies in his past, there have been discrepancies of 80 points or higher! By the law of averages, things should start evening out. There are also other things to look at as well.
His actual bat speed, the thing that hitters fear losing the most, has not really seen a decline yet. The average speed at which Harper has swung a bat, at least in the three years of which we have data, has held roughly steady – 75.5 mph in 2023 to 74.0 mph last year to 74.4 mph this year. Hard hit rate, average exit velocity, all the things one looks at are all holding steady as well. He’s just not hitting the fastball. Is it a timing thing? Possibly. It’s hard to hit fastballs.
There is also, going back to how pitchers are attacking him, the issue that he isn’t seeing that many fastballs in the first place. Last year, he saw a fastball 52.8% of the time. So far in 2025? 45.2%. That’s a massive drop no matter who the hitter is. One would think that if a hitter is seeing velocity less often, when it does happen, it can be an issue. Those fastballs that are in the Heart zone at 94 miles per hour or higher? He’s swinging and missing more often.
It’s not all doom and gloom, but these are legitimate concerns to have.
Bryce Harper is not hitting as well this season as he had in the past. There are a myriad of things that are happening, but it’s likely that the scouting report on him is out: try and get him to chase the breaking stuff around the zone, but he can also be beaten right now with velocity in the zone. It’s a difficult place for him to be, but it’s also one that can probably be fixed. If it is a timing issue he’s having with the fastball, one can probably reasonably assume he’ll get the timing back at some point. Once that happens, we can probably expect all of those numbers that are down – the Heart of the zone issues, the struggles against fastballs in general – snap back to career averages. It’s what good hitters do and Harper is a good hitter. It’s concerning, yes, that this is happening and we really shouldn’t think otherwise. However, before you go writing off Harper as starting his decline phase, pay attention to these trends as the year progresses. If he can get to the, ahem, heart of the matter as far as where the issues lie, the lineup will improve and the Phillies will be dangerous all over again.
It’s probably just a matter of time.