The question seemed unthinkable a year ago: What’s wrong with Paul Skenes?
After posting sub-2.00 ERAs in each of his first two seasons — the first qualified pitcher age 23 or younger to accomplish that since Dwight Gooden in 1984-85 — Skenes enters his first start of August on Wednesday with an ERA approaching 4.00.
The issue is not tied to one glaring flaw. It’s several small declines that reinforce one another. A little less velocity. A little less movement. Slightly worse command. More balls in the air. A weaker defense behind him. Individually, none are alarming. Together, they’ve transformed the best pitcher in the NL last season into merely a very good one.
It all leads to another question: Can the elite version of Skenes return? Let’s diagnose what’s gone wrong and look at whether the 2024-25 version of Skenes could return down the stretch.
The most obvious change is that Skenes is not throwing as hard as he did his first two seasons, when his fastball averaged a blistering 98.8 mph as a rookie in 2025, and 98.2 mph last season. His velocity is down to an average of 96.9 mph this season, and it’s been in decline throughout the season.
“I think it’s funny [reporters] only ask [about velocity] when I don’t have a good outing,” said Skenes during the All-Star break in Philadelphia. “… I don’t think velocity is something I need to pitch well. I think it’s probably the first time in my career the velo has kinda dipped. It’s not something that I’m stressed over at all. I’m healthy. I’m feeling good and still pitching at a high level.”
But the decline matters. A loss of nearly 2 mph may not sound dramatic, but at the Major League-level? It’s enormous. MLB batters are hitting .219 against 99 mph fastballs the last two seasons, compared to .242 against 97 mph fastballs.
Skenes mirrors the league-wide marks: opponents hit .209 against his fastballs last year, but .231 this season. That’s still below the MLB average for hitters, but it’s one thing trending in the wrong direction.
Also keep in mind there were concerns about Skenes’ fastball shape coming out of LSU, one of the few blemishes on his scouting profile. He possesses well-below-average vertical movement on his fastball. Less velocity can make a suspect shape more vulnerable. Moreover, with less velocity generally comes less spin — his fastball spin rates are down by about 70 rpm — and that means less spin-based movement.
For a pitcher who built his arsenal around overpowering hitters, velocity decline can diminish performance on all pitch types. The run values of Skenes’ sinker and changeup have turned negative for the first time in his career.
Perhaps the most surprising metric is Stuff+, a metric that attempts to isolate the quality of a pitch independent of results. Skenes posted a 110 Stuff+ last season. This year, he’s at 98.
Last year, his raw arsenal graded roughly a standard deviation above league average. This season, by that measure, it’s merely average.
The velocity decline isn’t necessarily permanent, though. I asked two pitcher trainers and biomechanical experts at Driveline Baseball to analyze Skenes’ mechanics.
So perhaps a work in progress. A velocity bump would be huge for the Pirates’ stretch run.
The loss of velocity and stuff is tied to another issue. It’s not just the batting average allowed but also the quality of contact.
Skenes’ average exit velocity allowed has increased. His groundball rate has fallen from 51.1% as a rookie to 39.7% this season. More balls are being lifted, and more of them are leaving the park. He’s already surrendered 13 home runs, more than in either of his first two full seasons.
It also means fewer double plays induced, with Skenes losing opportunities to get himself out of trouble.
The underlying pitch metrics tell the same story. Hitters are missing his breaking balls by less — 4.9 inches on average last season versus 3.6 inches this year.
Skenes has also raised his arm angle to 26 degrees this year from 23 degrees the previous two years. While still a lower slot than most all pitchers, it’s up a bit, and perhaps another factor. Again, a little thing.
Slipping command and efficiency
Another area pitchers largely control is command. And, again, it’s not that Skenes is suffering from a staggering loss of command, but it too is going in the wrong direction.
Skenes’ walk rate has climbed to a still-good, but career-worst 6.3%. His 108 Command+ is excellent, but also slightly down from last season (112) and 2024 (110). Skenes’ percentage of pitches located within the confines of the strike zone dipped from 51% in each of his first two seasons to 46% this year.
Given his still-strong underlying command skill, those fewer pitches in the zone speak to a pitcher less confident in his ability to miss bats and overpower in the zone. It suggests a conscious choice — not skill loss. But more nibbling leads to less efficiency.
Skenes said before last season that his goal was greater efficiency — to be able to reach 240 innings pitched in a season. Instead, it’s going in the opposite direction.
The defense isn’t helping … and he’s a bit unlucky
Over the offseason, the Pirates consciously sacrificed some defense in exchange for a stronger lineup. It’s helped them climb into the NL Wild Card race, but it hasn’t helped Skenes’ performance. His expected ERA, or xERA (2.94), remains nearly a run lower than his actual ERA (3.90) suggesting the defense has amplified some of the decline.
Last year’s Pirates ranked seventh in Outs Above Average (+18). This year’s club ranks 22nd (-13). The club allowed a .281 BABIP last year, compared to .298 this season. More grounders are rolling through the infield.
This is an inverse of the situation his previous two years, when his ERA in 2024 (1.96) and in 2025 (1.97) were lower than his xERA figures (2.50 in 2024) and (2.65 in 2025).
Skenes’ expected numbers are not that much worse than a year ago. But a step back in stuff, command and efficiency — when combined with a porous defense — is inflating his overall numbers.
The encouraging news for Pittsburgh is Skenes hasn’t suddenly become ordinary.
His 24% K-BB% mark is elite. He’s sixth among all pitchers with 3.6 fWAR. He’s simply become a little less extraordinary in several ways.
Baseball is unforgiving at the highest level. Lose a little velocity. Miss a few more locations. Allow a few more balls in the air behind a weaker defense. Small changes become big results.
The encouraging part is that none of these trends suggests a broken pitcher. Small declines often require only small adjustments.
He’s been missing lately, but he’s not that far away.
