Matthew Liberatore has had an uninspiring start to his season. He has not been horrible, but many fans, myself included, were expecting him to improve or possibly ascend to a top-of-the-rotation type pitcher. Today I want to do a little meandering investigation into what has gone wrong with Libby and what we should expect moving forward.
Before we get to present-day Liberatore, it’s important to remember how he got here. On this date last year, he had also completed 10 starts but ranked 14th in baseball with a 1.7 fWAR. Through June, Liberatore was maintaining his impressive trajectory pitching to a 3.70 ERA and ranking in the top 20 in starting pitcher WAR in all of baseball. It is an easy narrative to follow. A former top prospect that has bounced between starting and relieving for a couple of years moves into the rotation in his age-25 season and pitches like an All-Star for the first half of the year. Then came July and August. Liberatore had a nine-start stretch where his velocity dropped, home run rate ballooned, and his ERA jumped close to 6. For his final act, Libby put together a solid September pitching to a 3.54 ERA with FIP and xFIP around 4.
That brings us to 2026. Libby is the Opening Day starter and undisputed leader of the pitching staff… and things have just not gone well. His walk rate has jumped over one per nine to 3.48. While this isn’t an awful number, it is not good enough for a command-first pitcher. Libby’s home runs per nine have also jumped from an acceptable 1.13 to a bloated 1.57. I wanted to take a closer look at Liberatore and see if there were any glaring issues in his underlying metrics or reasons for optimism.
Liberatore’s home run rate is elevated, but is that just because of his career-high 14.5% HR/FB ratio? We often talk about batters and their ability to pull the ball in the air to access power. Liberatore was solid at preventing this in 2025, allowing batters to pull only 15.4% of balls in the air. This season, that number has increased to 23.4%, one of the worst marks in the league, 12th worst out of 129 pitchers who have had at least 100 balls put in play against them. Liberatore’s velocity and underlying stuff metrics are similar to last season, if not a tick better, so what gives? With his elevated walk rate, could the home runs be up because he is falling behind more frequently and being forced to throw more pitches in hitters’ counts? To check this, I looked at the total percentage of pitches he has thrown in each count this year and last.
There is nothing alarming here. If anything, Libby is actually getting into slightly more favorable counts than last season. So, where are the walks coming from? Last season, in three-ball counts, Liberatore threw pitches in the zone 65% of the time. This season, his zone rate is down to 53% in three-ball counts. While this is hurting his performance thus far, it is better than a pitcher who has just lost control of the zone. This strikes me as more of an execution problem or even just small-sample-size variance than some kind of systemic issue with his approach.
Ok, I am satisfied that the increased walk-rate is a minor blip that is likely to even out as the season goes on. Unfortunately, I do not think count control is the culprit for Liberatore’s other issues, so we must forge ahead. Pitch mix has always been a hot topic when it comes to Liberatore because he has always had excellent breaking pitches and has had to navigate a pedestrian fastball. The narrative has been that if his fastball velocity dips at all, it won’t play at the major league level. Velocity has not been the problem, as both of Liberatore’s fastballs are up ~0.5 MPH. Perhaps his modest velocity increase has driven Libby mad with power and he is altering his pitch mix as a result? Here is the breakdown between 2025 and 2026.
Liberatore has reduced his sinker usage by a couple of percentage points, but is throwing his four-seam fastball much more this year, up 5%. The results have been even worse this year. His xwOBA against on four-seamers has increased from a bad .370 to a downright horrific .455. Interestingly, most of the additional damage is coming from lefties. You can see in the chart above that Liberatore has increased his usage to lefties from 17% to 27%. The pitch has been battered to the tune of a .694 xwOBA. Lefties are basically better than peak Barry Bonds against Liberatore’s four-seam. Not to overly simplify things, but that really is the story of Liberatore’s year so far. He is throwing his worst pitch more frequently than ever and getting absolutely punished for it. On his offspeed and breaking pitches, his results have been right in line with last season.
To look at this data from a more optimistic lens, Liberatore almost can’t do anything but get better. His fastball isn’t great, but it likely will not continue to get blasted around the yard at quite this rate, even if he doesn’t make any changes. With that said, it seems like the obvious answer is to dial back on the fastball usage a few notches while upping the breaking balls. Liberatore’s curveball and slider are both excellent pitches, both by pitch models and results. I don’t think it is as simple as throwing them 80% of the time, but he could bump them up from the 37% frequency with which he is now deploying them.
There were some big positives in Libby’s nine-strikeout performance against the Pirates in his last start. Not only were the results better (until the fifth-inning blowup), but he seemed to have a better plan of attack. His curveball was his most frequently used pitch (23%) and his fastballs were only used 28% of the time. Not only did Liberatore throw his curveball more frequently, he threw it harder than he has the last two years, averaging 81 MPH with the pitch (up two MPH). He also had a two-year high in RPMs on the pitch with an average spin rate of 3,116 compared to a season average of 2,960. The extra sharpness helped Liberatore strike out five batters with the pitch while generating six swings and misses. In addition to the increased curves, Libby also threw nine cutters (12%). This utilization is closer to his 2025 mix and up from the 3% he has used it so far in 2026.
I will be following Liberatore’s pitch mix closely the next couple of starts to see if he is making a concerted effort to minimize his fastball usage and rely more on the breakers, or if the Pittsburgh game was just a one-off day where he was spinning the ball particularly well.
After looking a bit more closely at Liberatore’s pitch data, I am convinced he will at minimum return to the solid version of him we saw in 2025. It seems he is just not getting away with any mistakes thus far and has failed to execute at his normal level in three-ball counts. The problem is, fairly or not, the Cardinals really need Liberatore to be better than he was last year if they plan to keep pace with the rest of the NL Central. To do this, Libby needs to find a way to steer clear of his fastballs as much as possible. He has abandoned the splitter that he worked on over the offseason after throwing only seven of them (all in the month of April). The pitch grades well from a movement profile, so hopefully he is still working on it in the background.
Going forward, I would like to see Liberatore increase his curveball usage to above 20% and stop relying so much on his four-seam fastball, especially when behind in the count. If he can find a third pitch, whether it is the cutter, the splitter, or the changeup, to give hitters something else to think about, he could be the catalyst that keeps this Cardinals train on the tracks a little longer.
