2025 SPs to Watch: Reese Olson

While many are familiar with Skubal and Flaherty, the Tigers have an under-the-radar arm poised to elevate their game to the next level.

Introduction

Reese pieced together a great, yet discrete 2024 in a buried Detroit market. His 3.53 ERA and 1.18 WHIP indicate a true #2 or #3 starter, despite a 68% left-on-base rate that places him well on the unlucky side of things. His process is of equal quality; his contact mitigation skills are world-class for his still solid CSW and swinging strike rate measures, placing above the 90th percentile in the former and the 70th in the latter. In a Tiger organization that coaxed the maximum out of Tarik Skubal and Jack Flaherty, I think it’s likely Olson will find the refinements to let him stick the “top of the rotation” landing. Here’s a breakdown of what makes him tick, and what I imagine will be focused upon in a potential breakthrough 2025 campaign.

Pitches

His most used pitch is actually a slider, which sweeps and drops more than one would expect at 85 mph, with few mistakes in location. The results are an assembly line of missed swings and weak groundballs against both sides of the plate, despite a zone rate 6 points below the league average. The swing-and-miss specifically could power a wind turbine; the chase and whiff rates run around the 95th percentile, and it surely means a bump in the usage rate is to come. Olson demonstrates his great feel for spinning the baseball with it as well, uncorking a slider 350 rpm greater than average on slightly below-average velocity.

His biggest weakness is his bland 94 mph 4-seamer. It can get some groundballs with a focus on low location, but a harsh characterization could call it dead zone. Its 37% usage against LHB, which is its exclusive role in the arsenal, is certainly too high. How far Olson can go is dependent on this pitch’s role: if it continues to be his most used pitch in the weak-side platoon matchup, he will struggle to level up.

The changeup is similarly nasty to the slider, with its -1 inches of IVB getting tons of swings and misses. He has the Snell approach with it - all down, nothing in the zone - but it fails to achieve the same contact suppression Blake manages. Perhaps the 4-seam’s emphasis on the lower third limits the value of their tunnel, but it’ll be difficult for him to dance with the heater up with its profile. Intriguingly, it dominated RHB in 15% usage for a 53% whiff rate and 29% ICR, something that it generally is not meant to do. If it can keep even half that success, the slider/changeup duo has the makings of a killer foundation that covers both sides of the plate.

The sinker is the second half of his plan against RHB, posting the top mark of 45% usage. Its dominant use in same-hand matchups is reminiscent of Tarik Skubal, who utilizes his sinker with even more frequency to completely stymie the opposition. For instance, Olson’s 2-steam didn’t allow a home run all year in 361 pitches despite contact rates over 90%. With such an underperforming fastball, I’m curious if he starts trying some more frontdoor sinkers against LHB, a tactic that his ace also incorporated with success this past year.

He struggles to locate his curveball that sweeps nearly a foot, and the results are as unimpressive as one may imagine. The strike rate is low, it doesn’t mitigate hard contact in typical Reese Olson fashion, and it is only average in getting whiffs. In fact, it allows an xWOBA over .400 against LHB, its intended target. The shape isn’t particularly interesting and it feels more like a reprieve for the hitter from more changeups and sliders than a surprise weapon. It may be downgraded from a member of the supporting cast to an extra in Reese’s 2025 feature film.

Olson has a clear three-pitch mix to build around in the slider, changeup, and sinker.

The Georgian’s clear issue is LHB, which causes him to throw far too many 4-seamers and curves. My solution? A low-vert cutter, which would fit into the rest of his low-carry repertoire well. His slider proves he can spin the ball well glove-side and it wouldn’t take much refinement to get superior results to the status quo. While researching this article, I saw Lance Brozdowski promoting a similar idea. I’d accuse him of stealing the idea, but he came up with it 18 months before I did. I’ll let him off the hook this time.

Conclusion

I’m curious if Olson continues to pursue a low zone rate approach to take advantage of his great chase rates. He managed to keep his walk rate in check with the strategy in 2024 (7%, half a point below league average) while also preventing hard contact better than almost anyone. Without any improvement, Olson definitely will be able to run a 3.75 ERA in Comerica (the newest projection system, OOPSY, predicts a 3.79 ERA), but a true third option for LHB would push him consistently into 3.50 territory and below. Out of all the pitchers I plan to cover, this is clearly the safest.

Sources

PitcherList

FanGraphs

BaseballSavant

TJStats’ Pitching Summary