A closer look at Tyler Matzek’s injury plagued 2022 season

The bullpen was a bright spot for the Atlanta Braves in 2022, as its production was second in all of MLB in fWAR. However, even with relief corps doing a fantastic job as a unit, Tyler Matzek had his worst year since returning to MLB action in 2020.

With a minimum of forty innings pitched, the 2021 postseason hero was the worst reliever in MLB in terms of expected fielding independent pitching (xFIP). With an xFIP of 5.59 in 2022, it was a gigantic drop-off from his 4.01 in 2021 (82nd of 144 among qualified relievers), and 3.00 in 2020 (20th of 178 qualified).

From a more traditional standpoint we can see that from 2020-2021 Matzek looked solid with an ERA of 2.64 (69 percent better than league average in that span), with a 1.169 WHIP, and a SO/W ratio of 2.55.

In 2022 Matzek had a 3.50 ERA (17 percent better than average), with a 1.260 WHIP, and a K/BB ratio of 1.24.

While we can argue for days what the best statistic to use to evaluate players, it is pretty evident that Tyler Matzek had an off year in 2022.

We know that he was most likely dealing with symptoms of an impending injury at some point during the season, especially since it was announced on October 12th, 2022, that he will be having Tommy John surgery. Even with the cloud of injury hanging over him, we can dig into the numbers and see what changed in his approach that led to his statistical drop off.

What changed for Tyler Matzek?

The first thing that draws the eye are a high and low strikeout rate — both worsts since he came back in 2020. His 1.24 K/BB ratio was much worse than the league average of 2.75.

Matzek walked six batters per nine innings pitched. Of relievers with at least 40 IP, he had the fourth highest walk rate in MLB; about one in six batters he faced ended up walking.

His strikeout rate on his fastball dropped drastically (36.7 in 2020, 22.3 in 2021, 15.8) while his fastball usage has gone way up (more on this later). His slider strikeout rate also dropped from 50.0 percent in 2021 to 36.1 percent. Overall, his 19.6 percent strikeout rate was 175th among relievers with at least 40 innings pitched.

There are quite a few variables in play regarding his drop in peripherals.

First, it should be noted that his pitch selection in 2022 was much different than the past. He was using exclusively his fastball and slider in 2022, completely abandoning the curveball (he threw one) and the cutter. His fastball usage shot up to 76.7 percent of the time from 70.7 in 2021 and 61.9 in 2020.

What is interesting is that while the fastball was used much more often than in the past, Matzek lost control of it. With his fastball, his out of zone rate has jumped every season since his return in 2020. It went from 41.1 percent in 2020 all the way up to 52.7 percent of the time in 2022. It does not take a rocket scientist to figure out that if your most thrown pitch lands outside of the zone more than half of the time, it is going to lead to a lot of walks. Even worse: if you look at all pitches thrown, his out of zone percentage creeps up to 56.1 percent.

Along with missing the strike zone more often, Matzek’s pitches took a drop in velocity. This makes sense considering he ultimately ended up needing Tommy John surgery. His velocity was down from 96 MPH in 2021 to 94.1 in 2022 on his fastball. On his slider it dropped from 84.7 MPH in 2021 to 83.2. For reference, the league average perceived velocity for 4-seam fastballs in 2022 was 93.8 MPH. For a slider, the average was 84.5.

With Matzek’s change to exclusively a two-pitch approach, it appeared to help hitters dial in their swing on pitches that were thrown inside the strike zone. Hitters whiffed on Matzek’s fastball inside the zone at their lowest rate since he re-joined the majors with a 19.8 percent rate. On his slider, his whiff rate plummeted from 31.5 percent in 2021 to 20.6 percent of the time in 2022. The lack of velocity on the fastball was likely key here as well.

Strikeout rates and walk rates are not the only areas that Matzek struggled with in 2022. Hitters were having an easier time hitting the ball too.

With a drop off in velocity, lower in-zone whiff rates and a higher rate of fastballs thrown, it would seem to lead to more squaring up on the ball, and that is exactly what happened.

The barrel rate against him sky-rocketed, especially the fastball. His barrel percentage as a whole jumped from 3.4 percent in 2021 to 7.7 percent in 2022. On his fastball specifically, it was up to 9.0 percent in 2022.

It appears the higher barrel percentage also allowed hitters to keep the ball off the ground easier. Matzek never had a ground ball rate lower than 41.9 percent prior to this past season. In 2022, it was 35.0 percent. This is due to a career low topped percentage (24.8) and a drastic shift in averagelaunch angle on his fastball (14 degrees in 2021 to 22 degrees in 2022).

With all these changes factored in, Matzek’s xwOBA on his fastball and slider both went up in 2022. His xwOBA on his slider jumped from 0.183 in 2021 to .272 in 2022. His xwOBA on his fastball jumped from .298 in 2021 to .333 in 2022.

League average against a 4-seam fastball in 2022 was .340, so it is not like Matzek’s 4-seamer was the worst In the league, but there was a definite drop-off. That league-average figure, of course, involves a bunch of starters working their way through a lineup multiple times. As far as the slider goes, the league average xwOBA was .268, so Matzek was just slightly worse. Still though, a difference of .089 in xwOBA from 2021 is a big drop off.

Summary

Tyler Matzek had a down year, there is no doubt about it. Sure, he was battling an injury, and that is a legitimate excuse for a downturn. This is not to say that Tyler Matzek is a bad pitcher, or that the Braves should just cut him because he is injured.

What we can see is what changed, whether it was due to injury, or pure bad performance. We do not know exactly when his impending injury started to play a role in his regression, but we can see how Matzek regressed.

In a nutshell, the main issues that resulted in a decline are as follows:

• Loss of control: 56.1 percent of his pitches were out of the zone, which has increased every year since he joined the Braves.
• He has abandoned all but two pitches, the four-seamer, and a slider. Not always a bad thing, but his velocity is down on both pitches, along with his control issues.
• Hitters can sit back and wait on a pitch they like in the zone, drastically decreasing his whiff rate inside the zone from 2021. This is mostly due to loss of control and lack a pitch variety. This has also increased hitters’ barrel percentage against him
• Hitters are not hitting on top of the ball as much, which has resulted in them getting a more optimal launch angle and hitting fewer ground balls.

Here is to the hope that most of the 2021 postseason hero’s issues were due to an impending injury, that he can make a swift recovery, and that he can make the adjustments that need to be made so he can come back and be a formidable reliever once again.