Thoughts On Spencer Strider's Struggles

Atlanta's strikeout king can't seem to rediscover his old form, but I think he can get there

Sorry for the delay in getting this deep dive out, but I wanted to have some time to digest Strider’s start last night and his comments about it after the game.

“I can’t compete in the strike zone, and that’s it.”

Spencer Strider’s words to the media after last night’s disastrous start to the Chicago White Sox, where he allowed seven runs on ten hits and couldn’t record an out in the fourth, have some people on social media losing their minds. There are calls to do everything from moving him to the bullpen as a closer to even trading him (for Arizona Diamondbacks second baseman Ketel Marte, specifically, who is rumored to be available this winter due to a clubhouse dispute).

I think he’ll be fine…eventually.

Let’s talk about it.

The velo isn’t the problem

Spencer Strider tied a season-high with an average 96.2 mph velocity on his four-seam fastball last night. Both the ceiling and floor were higher, too; his max was 97.4 and his slowest was still 95 mph.

It didn’t matter. The White Sox put seven of his sixteen fastballs into play at an average exit velocity of 88.5 mph, including one home run.

The slider velocity was improved, as well - 84.6 mph, its second-highest mark of the season. While it wasn’t above the magic number of 85 mph¹, the velo wasn’t a problem for Strider last night.

Maintaining that velocity was, to an extent, easier said than done last night. While Strider was able to reach back and get 97 when needed in the 4th inning, most of his fastballs were in the 95 range. Not something I’m too worried about; a normal offseason will get him back to where he needs to be in terms of stamina.

The pitch’s movement is the problem

Strider discussed this last night after the game, telling reporters (including MLB.com’s Mark Bowman), “I can't compete in the strike zone, and that's it,” when answering what the main issue was on Monday night. “So, my fastball just isn't getting outs. It's not a contact pitch, and it's not moving the way that I need it to move.”

A look ‘under the hood’ bears this out.

In Strider’s most dominant seasons, his fastball averaged an elite induced vertical break of 18.4 inches, as compared to a league average of just 16 inches. What this means, simplified, is the ball’s backspin made it look like it dropped two inches less than the average fastball. Every pitch that’s thrown on a straight line off of an elevated mound will drop, because gravity is something your arm can’t overcome. But the backspin makes it look like it’s not dropping, or even like it’s rising in some outlier instances.

Spencer Strider’s fastball used to do that exceptionally well. It’s not doing it right now.

His average in 2025 is just 16.3 inches of IVB, right in line with what everyone else is doing across baseball. Remember, the goal for a pitcher is to do something different than everyone else, whether that be your velocity, movement, locations, or sequencing. Strider’s fastball isn’t doing anything different than what most other mid-to-upper 90s fastballs are doing.

And because he can’t trust it in the zone, it messes with the entire arsenal.

Strider can’t effectively sequence

The Spencer Strider playbook has been to use fastballs in the zone to get ahead in the count and then drop a slider off the table for a punchout. After the 2023 NLDS against Philly, where they executed a game plan of fouling off fastballs and sitting on the slider, hoping to get one in the zone, he added a curveball to get whiffs as a tendency breaker.

But right now, he can’t work that game plan.

“When I can't throw my fastball in the strike zone, obviously that gives the hitters a leg up. Then, my slider is an effective pitch, but not if I'm behind in counts or not making guys swing. Then inevitably, if I throw it in the zone, it's getting crushed.”

No one’s scared of Spencer’s fastball, except Spencer himself. This lets them sit on the slider and like he said, crush one in the zone.

In 2023, opposing hitters hit .154 with a .269 slug on Spencer Strider sliders in the strike zone.

In 2025, they’re hitting .230 with a .452 slug on the exact same pitch.

(data courtesy of Statcast)

And it’s because they can sit on it. Luis Robert Jr’s 4th-inning homer last night was a great example of this. Strider opened him with a slider in the bottom of the zone for a whiff, and then went back to the exact same spot with a second slider. Robert didn’t miss a second time.

If Strider trusts his fastball to get a whiff, do you think he throws the exact same slider twice to open an at-bat? One of those two pitches is likely a fastball.

Is this fixable?

Short answer: We don’t know for sure, but I’m not betting against Spencer Strider.

Strider’s April 2024 elbow surgery was an Arthrex InternalBrace™, which is a newer option for pitchers who are dealing with either damage to their UCL (which Strider did not have) or some sort of instability to the elbow.

And unfortunately, we just don’t have a ton of data on the long-term return to play of players who receive that specific repair. I have access to an industry database of college and MLB players that have suffered various arm injuries and how they handled it - Tommy John, non-surgical rehab, or internal brace surgery.

The Tommy John list has 2,612 players going back to 1974 when the “guinea pig” for the procedure, Dodgers starter Tommy John, had what was then an experimental surgery to try and save his career.

The Internal Brace list has a total of 55 names on it, with the first being from 2016.

We just don’t have a very deep track record of how MLB pitchers come back from this surgery.

But despite that, I’m not doubting Spencer Strider. He developed into the version of ‘Quadzilla’ that we knew after his first Tommy John surgery, which he had while at Clemson University. He went into his rehab with a purpose - to understand why he got hurt and how to prevent it from happening again.

(Former Braves beat writer Justin Toscano of the Atlanta Journal-Constitution wrote a fantastic article about Strider’s journey back in 2022.)

I have zero doubt that if it’s possible to resume his old form after this elbow surgery, Spencer Strider will do it. He built it once; he’ll do it again.

1. It’s hard to have a bad gyro slider above 85 mph