Sorting out Carlos Martínez’s 2021 performance

Writer’s note: I made the ill-advised decision of compiling data for this article before Carlos Martínez pitched against the Rockies. My plan was to see if I noticed anything in his numbers, then update the stats in this piece to account for his start over the weekend. Given that his ankle injury from Friday tanked his velocity, spin rate, etc., I’m going to toss out his most recent game for the purpose of this post.

Suffice it to say that Carlos Martínez’s first month-plus has been an enigma of sorts. His back-of-the-baseball-card stats tell a tale of two seasons while the advanced metrics aren’t quite sure what to make of anything. You can conveniently draw a line between his first three starts of 2021 and his next three, so those are the timeframes through which I’ll frame this article.

Those two columns work out to ERAs of 7.80 and 0.84, respectively. Although several ERA estimators give pause to the notion that Martínez turned a corner after his rocky start to the year.

The further down this table you go, the more predictive power each metric has. To that end, the cause for concern also increases as you work your way down. FIP says Martínez has pitched better, but looking at ERA exaggerates the jump. This makes sense: his walk rate is slightly up (5.9% to 6.3%) and his strikeout rate is slightly down (14.7% to 12.5%), but FIP rewards pitchers who keep the ball in the park and Martínez hasn’t allowed a homer since April 10th. xFIP, meanwhile, sticks pitchers with a league average homerun-to-flyball ratio, so it’s not going to give Martínez credit since his flyball rate has remained virtually the same (32.7% to 34.9%). Finally, SIERA, essentially a hodgepodge of a bunch of these metrics, goes so far as to think Martínez has regressed lately.

To make matters even more complicated, Statcast is squarely in the “Martínez has legitimately been pitching better” camp.

According to Statcast, the key has been limiting quality contact. For context, the league average wOBA (weighted on-base average) on a ball put into play this season is .365. If a ball is hit well enough to be categorized as “barreled,” that number jumps all the way to 1.318. Martínez has more than halved his barrel rate and also slashed his overall hard contact rate, which explains the dip in allowed exit velocity and “expected” wOBA stats, which tend to be more predictive of future performance.

“Less quality contact=better pitching” makes sense, but that’s an interesting trend given the plate discipline data for opposing hitters.

His first-pitch strike rate is up, which is a positive sign for obvious reasons. What’s most intriguing to me is that the overall contact rate against Martínez is holding steady, but a greater share of that contact has been on pitches in the strike zone, which would intuitively be a “worse” profile if the goal is to suppress quality contact.

But what definitely makes for a better profile is Martínez’s pitch velocities as of late.

With the exception of the slider, Martínez has added an extra mile-per-hour or so across the board. Despite this, his average spin rate on offspeed and breaking pitches has actually declined over his past several starts.

As for what all of this data means, I would assert that more of these bellwethers are more favorable than not. If the “stuff” we’ve seen from Martínez yields the type of contact that he’s been inducing from mid-late April onward, then Martínez remaining a strong contributor to the Cardinals’ rotation is very much feasible. At the same time, though, it will be worth monitoring his peripheral numbers as the season progresses.