Last week Mets360 touched on home runs during Spring Training and specifically noted that Steven Matz has been prone to the gopher ball during his tune-ups this year. While there could be a counter argument that Spring Training is meant for testing new techniques, which can lead to stuff getting torched, there’s certainly some interesting figures around Matz’s 2018 season in relation to hit trajectory and home run rate. Last year Matz performed above the National League average of .82 Ground Ball to Fly Ball Out Ratio (GB/FB) with a mark of .97 of his own. This could be viewed as a positive, as it goes without saying that inducing weak contact via a ground ball is one of the best results as a pitcher; If the ball is within a reasonable range of the defenders, then there is 98% chance that it will be converted into an out. However it’s when the ball leaves the infield where the southpaw is getting into an unusual amount of trouble. Matz falls eight innings short of being a qualified starting pitcher in the category of HR/FB, however he would rank second worst in the majors in this regard between Dylan Bundy and Luis Castillo. His HR/FB ratio of 12.8% was well above the league average of 7.7% (for context, Jacob deGrom posted a 4.5% rate last year). Taking a dive into the performance metrics might shed some light as to where Matz is going wrong and what to look for in 2019.

Matz has an array of offerings, ranging from a sinker which touches 94 mph and a solid changeup at 84 mph; his curve sits at 78 mph and is actually below league average in terms of spin rate according to Statcast. In 2018, for the first time in his career, Matz’s curveball was his third most used pitch as he started to rely on his changeup more often. He occasionally breaks out a slider which has recently proven to be a solid option in his repertoire.

There is a metric called Effective Velocity or EV, which measures individual pitch deception by factoring in sequencing, velocity ‘tunneling’ and how far a hitter has to move to make contact with his bat. This is all compiled to basically say ‘how fast a batter perceives a relative pitch to be thrown.’ Last year Matz posted a mark of 90.1 EV with his slider, the best rating of all of his pitch types. Opponents had a .296 slugging percentage against this pitch as well, although it was only used 8.4% of the time. Here’s how all of his pitches of 2018 compare (note that he very rarely mixed in a four-seamer).

Pitch Percentage Used Slugging Percentage Fly Ball Percentage Effective Velocity (mph)
Sinker 59.4% .436 24.6% 87.8
Changeup 15.8% .490 29.6% 87.0
Curve 15.7% .371 17.1% 86.6
Slider 8.4% .296 17.8% 90.1


From the table above we can see that Matz relied heavily on his sink fastball to the point that its EV was less impactful than we would believe. The sinker and changeup were also more prone to being hit in the air (despite sinkers being known for their ground ball tendency), accounting for 20 of the 25 homeruns given up last year. These figures suggest that Matz should consider easing back on the usage of his changeup and reallocate slot time to his slider.

As someone who finished organized baseball at 18 years of age, I’ll admit that my view of the sport comes with a relatively untrained eye. However the graph below captured my interest as I noticed the slider as an outlier of spin rate and movement among Matz’s offerings. Sitting in between his sinker (which is effectively a fastball) and curveball in velocity, the slider is also a change of pace in terms of movement which could be throwing batters off their mark. This is also supported by the chart above by the slugging percentage against each offering. What’s interesting though is how similar the sinker and changeup are in terms of spin rate and movement and also their EV. Could Matz not be hiding his grip well enough or is he tipping his arm slot angle? This would require a deeper look into the film, however I believe that Matz would benefit from an increased slider usage and possibly the development of a different fastball. The sinker seems to be generating the same motion as his changeup and does not allow Matz to effectively pitch up in the zone, which is where we are seeing hitter’s vulnerability.

In addition to pitch type, Matz has shown a strong tendency in regards to home runs by zone (graphic below), where the inside part of the plate to right-handed batters gives him the most trouble. This is interesting when you consider Mets pitching coach Dave Eiland’s most recent comments regarding a renewed team focus on pitching inside.

If Matz can find a way to reduce his HR rate then it’s safe to say that the Mets will have a ‘1D’ option to team up with their other three ace caliber pitchers. For so long, Matz has shown glimpses of star potential, only to be slowed down by injuries. It’s possible that the injuries are causing Matz to overcompensate in certain areas of his delivery, thereby tipping his pitches. It will be interesting to see how the 2019 season develops for the 27 year old entering his prime years.

7 comments on “Steven Matz and hitting trajectories

  • BVac

    I remember Matz struggling some last spring as well, so hopefully you are right and he uses spring to tune up some new pitches. Maybe he’s been working on the slider you say is underused!

    • Chris B

      What’s interesting is that the slider was effective last year despite Wharthon being gone, who was known for developing the pitch well.

  • David Klein

    Ronnie has mentioned that Matz tips that he’s throwing his changeup so maybe that’s partly why it gets tattooed

    • Chris B

      That’s good to note David – thanks! I’ve seen networks experiment with different camera views in ST. There’s one from the catchers vantage point that may allow us to pick up on these things from our couches.

      • Hobie

        I’ve always liked that catcher’s-eye camera angle. Mets used it a lot 60’s-70’s and I can still picture Koos’ curve dropping off the table. Hope we see more of it again.

  • Rob

    I can see him with Al Leither type career. Inconsistent and injuries then got it all together.

  • Chris F

    Matz throws high far too much. He has release point issues. I think he has pitch finishing issues too. As a result he throws a lot of middle middle and up. For him to get lower, he backs off, the arm slows, and more issues.

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