Breaking Down Zebby Matthews’ Debut Campaign

After a rapid ascension up the ladder in 2024 what’s on the development plan?

To say Zebby Matthews made a fast run up the Twins’ minor league ladder would be an understatement. Coming into the 2024 season, Matthews — a 2022 eighth-round draft choice from Western Carolina — had worked only 108 and ⅓ professional innings across three minor-league levels.

Due to his performance and the Twins’ need for healthy starting pitching, Matthews raced from High-A Cedar Rapids to Target Field last season, pitching at four different levels along the way.

He began the season with four excellent starts for Cedar Rapids (1.59 ERA) highlighted by a spectacular 28-0 strikeout-to-walk ratio. That earned him a promotion to Double-A Wichita, where he ran his walk-less streak to 141 consecutive batters, provided a 1.95 ERA across 10 outings, and produced another eye-popping strikeout-to-walk ratio (63-6).

It wasn’t until he reached Triple-A St. Paul that Matthews found much resistance from opposing hitters. In 19 innings there his ERA was 5.68, despite a 23-1 strikeout-to-walk ratio. That elevated ERA was fueled by four home runs, more than he’d given up (3) in 78 combined in High-A and Double-A innings.

When Joe Ryan went down for the season with a shoulder strain, Matthews completed his ascent and was pressed into service for a Twins team that was starting to fade. He made nine starts while the big club fell from contention, posting an unsightly 6.69 ERA in 37 and ⅔ innings. While he maintained his strong strikeout-to-walk ratio (43-11) in his first taste of the majors, he also served up 20 extra-base hits, including 11 homers.

Despite the rocky MLB debut, Matthews is viewed highly in prospect circles and figures to be squarely in the picture for a spot in the Twins’ rotation come 2025 Spring Training.

Let’s dig into his major league work, small sample that it is, and try to pinpoint what he might try to improve next season.

Scouting Report

When FanGraphs published its 2024 update to the Twins prospect rankings in June, it foreshadowed both the team pushing Matthews up the ladder quickly and the challenges he’d face as the competition got stiffer. They lauded Matthews’ control of a five-pitch mix, with his fastball, slider, and cutter earning high marks. Here’s a lengthy excerpt:

Matthews has barely walked anyone the last half decade. Since his freshman year at Western Carolina, he has walked 48 of the 1,440 batters he’s faced (as of list publication), which is a (takes out magnifying glass) 3% rate. This is a fairly extreme control-over-command profile. Put on Matthews’ tape and he’s living in the zone with incredible consistency but isn’t dotting his pitches exactly where he wants. Because of the way his fastball plays in the zone, though, that’s fine for him. He generates a ton of whiffs up and to his arm side despite a downhill approach angle because of ride and deception. Matthews’ slider and cutter pair nicely with one another, and some of them have dastardly late bite. His sliders have enough due south movement to play as bat-missers against lefties. That’s an important component because Matthews lacks a good changeup; in fact, his changeup usage has dipped substantially this year. There’s enough here to project Matthews as an efficient no. 4/5 starter, and probably soon. Given his age and build (a barrel-chested 225 pounds), the Twins might want to hit the gas here just in case, as with some other players of this sort, Matthews is currently peaking athletically.

In hindsight, the parts of the report discussing Matthews’ “control-over-command” profile and his lack of an effective changeup were particularly prescient.

Control-Over-Command

Even though command and control often are discussed together, they don’t mean the same thing. Control describes the ability to throw the ball over the plate. Command refines that, describing the ability to locate pitches to more precise locations in and around the strike zone.

Given the numbers I’ve shown you, you’ve surely gathered that Mattews throws strikes. His combined minor league strikeout-to-walk ratio last season was 114 to 7. While we don’t have Statcast data for Matthews in Cedar Rapids and Wichita, his outstanding results at those lower levels indicate that his stuff was good enough to live in the strike zone without being overly precise around its edges.

That wasn’t the case when he moved up to AAA and the majors, where better and more experienced hitters were ready for pitches in the middle of the plate.

Data from Baseball Savant

The table shows that opposing hitters had great success against Matthews in the heart of the plate. While the samples at both AAA and the majors are small, the expected stats based on the quality of contact Matthews allowed support the idea that he was hit much harder in the middle of the plate than on the edges.

Among the 473 MLB pitchers to throw at least 500 pitches last season, Matthews’ 29.1% rate of pitches mapped in the “heart” of the plate by Statcast was the 80th-highest. Conversely, his 40.4% rate of pitches in the “shadow” zone ranked 400th on the same list.

So, he was in the middle of the plate much more than most pitchers, and on the edges of the zone much less than most pitchers. That’s not a great combination and was consistent with the scouts’ “control over command” assessment.

Southpaw Struggles

Opposing left-handed hitters particularly enjoyed facing Matthews. They produced a very healthy .315 / .382 / .620 triple-slash line, good for a .425 wOBA fueled by 8 homers and 4 doubles.

Matthews worked with his whole five-pitch arsenal against lefties, leaning on his four-seamer and slider most, but also mixing in his changeup, cutter, and curveball more than 10% of the time each:

Data from Baseball Savant

But only his slider was an effective option.

His cutter, a fairly platoon-neutral pitch type for most pitchers, was hit very hard and opposing hitters also had no difficulty with his four-seamer.

As the scouting report foretold, his changeup, traditionally a weapon for right-handed pitchers to neutralize lefty hitters, generated decent results when it was put in play, but was heavily negative from a run-value perspective because Matthews could not consistently throw it over the plate:

Sixty percent of Matthews’ changeups to left-handed batters went for called balls and just 23.6% of them landed inside the Statcast strike zone.

That lack of command meant left-handed hitters didn’t have to respect anything that moved down and away. Instead, they could take a straightforward plan to look for fastballs up or cutters and breaking pitches moving toward them.

Right-handed Refinements

Matthews held right-handed hitters to a slightly less damaging .306 / .333 / .500 (.358 wOBA) line by working with a streamlined arsenal (four-seamer, slider, cutter), but his lack of precise command of a key secondary was again a detrimental factor:

Data from Baseball Savant

His cutter was his best pitch for righties, and the four-seamer was passable. But, much like his changeup to lefties, Matthews’ slider — which you’d expect to be a primary weapon against same-handed hitters — was a big liability because he didn’t throw enough of them on the plate:

That pitch was his best option for drawing a chase and a swing and a miss (50% whiff rate) but only 31.5% of them landed in the strike zone and 39% went for called balls.

Going Forward

Taken together, the previous two sections boil down to Matthews being limited to working inside the strike zone — too often in the heart of the plate — with his fastball and cutter, and throwing his breaking and offspeed pitches outside the zone:

Data from Baseball Savant

In some ways, that’s by design. Those changeups and sliders are meant to draw chases and swings and misses. But, Matthews went to his four-seamer and cutter about 74% of the time when he was behind in the ball-strike count. Of the 20 extra-base hits he allowed last season, 13 came against four-seamers and cutters.

That all suggests he needs to find a way to throw more of his other pitches for strikes, to take some of the pressure off his fastball and cutter, and to make his approach in the zone and behind in the count less predictable.

The data above suggests he can command his curveball well enough, perhaps turning to that pitch more frequently in certain counts is a potential solution.

There could also be adjustments in his mound positioning or target locations, especially against right-handed batters, to get more of those sliders on the plate and make it more difficult for hitters to discern his cutter from his slider from his curveball.

I also will be interested to see if we start hearing reports of Matthews tinkering with his arsenal this winter.

Many pitchers who are adept enough at supinating their hand and wrist to spin multiple types of breaking balls and throw a cutter, as Matthews seems to be, struggle to throw and command effective changeups, which usually require the opposite release movement (pronation).

Those pitchers — including Joe Ryan — sometimes find offspeed refuge in ditching traditional changeups and moving to split-finger options that don’t require pronation. That may be a fit for Matthews as he searches for an offspeed option that he can get over the plate.

The pitch quality models graded all five of Matthews’ pitches around league average. His raw stuff isn’t going to blow anyone away, but it’s plenty good enough to be effective if it’s deployed well. A few small tweaks and a higher level of execution that could come with experience could make a world of difference.

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John writes for Twinkie Town, Twins Daily, and Pitcher List with an emphasis on analysis. He is a lifelong Twins fan and former college pitcher. Follow him on Twitter @JohnFoley_21.