Where is the Real Steven Matz?

Steven Matz has a wide gap between his ERA and his FIP. I take a look at which is the real story and highlight some concerns as well as some areas of promise.

That last Steven Matz start was brutal. He allowed three home runs and eight earned runs in three innings and saw his ERA jump from 4.56 to 7.01. That’s a tough start to the year that is worth analyzing.

The new signing has had a start to the season that is very un-Steven-Matz-like. He’s getting whiffs at an above average rate despite being a heavy sinkerballer, he’s not getting ground balls, he’s striking out more than ten batters per nine innings, and he’s getting hit hard.

It’s no wonder that all of these things add up to a FIP (3.81) that is almost half of Matz’s ERA (7.01).

Usually a 30-year-old starter with over 700 innings under his belt is a known quantity. There can be small fluctuations, but generally, unless you’re Robbie Ray, you basically are what you are at that point. That’s not always true, but I don’t think anyone was expecting a Robbie Ray-esque season from Matz this year. Most of us would be happy with a mid-to-back-end starter.

Is Matz’s true talent closer to his FIP or closer to his ERA? His fWAR (which is based on FIP) is 0.3, which puts him on pace for around 2 WAR or just a bit less. That’s not great, but it certainly makes him a viable back-end starter. His bWAR (which is based on runs allowed per nine innings) is -0.7. That’s a guy who shouldn’t even be sniffing the majors.

Obviously St. Louis Cardinals fans are going to hope for the former. If he can bring his ERA down closer to his FIP (as opposed to bringing his FIP closer to his ERA), then he should be just fine this year. There are obvious warning flags though. We’ll start with the good and then get to the bad.

Let’s start with Matz’s bat-missing ability.

That’s pretty good company, other than Yusei Kikuchi (sorry Yusei Kikuchi). He’s just ahead of Kevin Gausman, who has been the best pitcher in baseball by a wide margin so far (according to fWAR) and just behind Max Scherzer, who, you know, is pretty good.

Matz has never been a bat misser, which isn’t surprising since he throws a sinker over half the time. Before this season, the right-hander’s career high whiff rate was just 23.4% and that came in 2020 when he only tossed 30 ²⁄₃ innings. Not counting COVID season, his highest whiff rate was 23% back in 2018.

This season, the league average whiff rate is 24.6%. He’s not exactly tough to hit; at least, he hasn’t been. That’s changed this year, though. Matz’s current whiff rate of 27.3% would shatter his career high if it holds over the course of the season. This whiff rate puts him comfortably above average in the 57th percentile.

He’s seen the biggest boost in his sinker, which usually sits around 18-20% in whiff rate, This season it has risen to a whopping 27.4%. You know how many qualified starters have a higher whiff rate with their sinkers? One.

Michael Lorenzen (29.5%) is the only starter above Matz, though Matz is also behind four relievers. He has thrown at least 65 more sinkers than every name above him, which makes his whiff rate that much more impressive.

The nearly 31-year-old has also seen a slight 2% boost in whiff rate with his curveball. That’s nice, but the sinker is really the story here because it’s the pitch that he lives and dies with.

The thing is that Matz’s sinker has been his worst pitch this year. Opposing hitters are batting .396 against the offering with a crazy high .473 wOBA and .436 xwOBA. To make things even worse, the average exit velocity against the pitch in 91.2 mph, the highest of his career outside of 2020, and only 20% of his batted balls against the pitch have been on the ground.

So, Steven Matz is taking a pitch-to-contact pitch and getting swings and misses at the cost of hard contact and fly balls. The pitch is simultaneously too hittable and hard to hit. If you would have told me that he was throwing a four-seamer instead of a sinker, it would be easier to believe.

This trend doesn’t even stop when he has bad games. Take the other night, for instance, when he got shelled by the Giants. Matz got a 33% whiff rate on his sinker. He also gave up three bombs with the pitch. That’s…not ideal.

Why is this happening? Well for starters, Matz likes to throw high sinkers. It makes him unique among Cardinals sinkerballers, but he has been hammered at the top of the zone.

Also note that his sinker has been hammered everywhere, not just the top of the zone, but still, Matz needs to be effective when he goes up top.

Take a look at his heat map next.

Basically, he’s throwing all his sinkers in the spot where they get crushed. Where does this leave us? Well, I can’t really say. Matz loves to throw high sinkers. It’s kind of his thing. I’m not expecting him to change that all of a sudden after a few bad starts.

He’s going to keep throwing high sinkers, and we just need to hope that opposing hitters stop teeing off of them. There is reason to believe this may happen.

Matz is currently running a .395 BABIP, which is well above his career average of .308, so I do expect to see him get some better results on contact soon. He also has a stranded runner rate well below his career average and the league average and that usually normalizes too. These are at least good signs that regression back to averages may be coming.

At the beginning of this article, I said that Matz’s home run rate this season is the exact same as his career average. That’s true. It was much lower until his last start, but it’s not like it’s absurdly high. The problem is that Matz is giving up fewer fly balls than usual, 5% fewer to be exact.

The problem here is twofold. He’s giving up fewer flyballs not because he’s getting more groundballs but because he’s getting more line drives. In fact, he has an insane 35% line drive rate allowed. That’s a big problem. The second issue is obviously a higher rate of fly balls leaving the yard. That is perhaps more concerning this season considering the effects of the dead ball, but he also gave up three of his four homers in his last start. In terms of home run suppression, he was great through five starts.

The high exit velocity (38th percentile) and high rate of hard hit balls (27th percentile) are concerning when thinking about home runs, so I am not yet ready to give him a one bad game pass.

The real problems for Matz has been line drives. His 35% rate is nearly 15% higher than his career average and nearly 13% higher than it was last season. On line drives, hitters have an .808 wOBA against Matz. When over a third of batted balls have an .808 wOBA on average, you’re going to have some problems.

So, has Matz simply gotten easier to hit or has he been unlucky?

None of the underlying statistics suggest that Matz has gotten worse. His pitches all have basically the same movement and velocity of previous seasons and he actually throws an above average amount of pitches on the edge of the plate. His meatball percentage (percentage of pitches thrown middle-middle) is really the only concerning number at 10%. That’s well above the league average of 7.2%.

That means that Matz has thrown 48 pitches middle-middle. He has allowed a .639 wOBA when pitching there, so he certainly gets hammered when he a makes a mistake.

35 of those 48 pitches have been sinkers. He throws his sinker about half the time, so a more equitable distribution would have seen only 24 of those meatballs be sinkers. That’s 11 extra meatball sinkers.

When throwing a meatball sinker, he gives up an even higher .701 wOBA. Sinker command is the real issue for Matz. He simply makes too many mistakes, and his sinker isn’t good enough to get away with it. He still throws 44.6% of them on the edge of the plate, which is above average, but he just throws too many of the over the dead center of the plate.

If Matz is going to improve, he needs to have better command of his sinker. The line drives are concerning, but I would expect that rate to bounce back to normal at some point. Throwing fewer meatballs should help with that, but so should better luck.

In 2020, Ben Clemens wrote at Fangraphs that batters control line drives more than pitchers and that a hitter’s line drive rate tends to fluctuate year to year. (I linked the article so that you could read it, because it really is an excellent summary of batted ball consistency.) That gives me much less concern about Matz, since it means that bad luck is the more likely culprit of the high line drive rate as opposed to lack of skill.

Matz’s line drive rate typically hovers between 19% and 22%. The only exceptions were COVID season (28.4%) and 2018 (15.4%). 2018 is really the only exception that counts.

I would expect Matz’s line drive rate to normalize. If it doesn’t, I still don’t expect it to be much above 25-26%. That would be a bad year for Matz, but, generally, pitchers don’t consistently allow high or low rates of line drives, so I wouldn’t be too worried about a higher than normal rate holding for anything after this year.

To make things clear for you since I’ve now written 1700 words on Steven Matz – his velo isn’t down, his pitch mix in the same, his pitch shapes are the same, and he throws the same pitches in the same locations. Basically, he’s still the same pitcher. He’s simply had a bad start to the year.

Much of that is because hitters are feasting on his high sinkers and hitting a lot of line drives. Better command of his sinker can help with this, but he simply needs better luck on batted balls.

Should we be concerned about Steven Matz? Maybe a little. But it’s way too early for me to have serious concerns about him not being a legitimate 4/5 starter. To answer my original question — he’s much closer to the Fangraphs version (0.3 fWAR) than the Baseball Reference version (-0.7 bWAR).

In fact, there are actually promising signs amidst his chaotic start. If he can get better batted ball luck and maintain his newfound whiff rates, then he could be in for a resurgence later in the season. I am more encouraged by the whiff rates than I am concerned by the batted data.

Pretty much nothing went right for him in his last outing, but I do expect him to not be that bad consistently. I know that’s a really high bar to set, but once his BABIP comes down and hitters stop being line drive monsters against him, he’ll settle into that back-end role that the Cardinals need him to fill.