Shoutout to Ben Cerutti of Birds on the Black after he reached out to me on Twitter following the first installment of this article, which you can read here. He is the inspiration behind this second article on Steven Matz’s unusual sinker. Give him a follow on Twitter at @stlfanbc7.
In the first article, I highlighted how Matz targets the upper part of the zone with his sinker. This is unusual among sinkerballers since most of them, including Marcus Stroman, pound the bottom of the zone with sinkers. This is traditionally the spot to go if you are looking for groundballs, which is generally why pitchers throw sinkers, but Matz has bucked this trend.
High sinkers make sense for Matz, especially since his go-to secondary offering is his changeup. The lefty’s changeup has a spin direction of 9:15 and his sinker has a spin direction of 10:15. This makes his sinker look more like his changeup. The spin direction is close which makes the pitches look similar to the hitter, but he would still benefit by bringing the spin direction on his sinker even closer to the spin direction on his changeup.
Even so, four-seamers typically do not have as much horizontal movement as sinkers because they are thrown with a spin direction closer to 12:00. This would mark a clear separation from his changeup, so the two pitches would look different. Throwing a sinker helps the two pitches look similar which increases his deception.
Additionally, Matz’s sinker and changeup have a similar movement pattern.
Matz’s sinker is the orange color and his changeup is the green. The only difference between the two pitches is that the changeup drops nearly twice as much (and it has slightly more run). Not only do the two pitches look similar, but they also have similar movement patterns. If a hitter incorrectly identifies a changeup as a sinker because of the similar spin, then he is much more likely to swing over the top of the changeup as it drops more than he was expecting.
The 30-year-old does not get great movement on his sinker. It drops 11% less than average while it’s horizontal movement is just 2% above average (essentially average). It is a different story for Matz’s changeup. It has 11% above average break vertically and 13% above average break horizontally. The pitch also has slightly above average velocity but is still 9 1⁄2 mph slower than Matz’s sinker. Since the changeup is the nastier pitch, it seems that Matz throws high sinker in order to allow his changeup to dominate. The pitches have similar spin and a similar movement pattern, but they do not have similar locations. If he kept his sinker down in the zone then hitters would be able to simply focus at the bottom of the zone which may help them key in more on his changeup. By varying his sinkers and putting more up in the zone, he prevents this from happening.
Matz’s changeup allowed just a .257 wOBA and .291 xwOBA in 2021, so it has clearly benefited from this approach. Another pitch which benefits is Matz’s curveball. The left-hander’s sinker and his curveball have exactly opposite spin which looks the same to a hitter.
The observed spin direction of Matz’s sinker is 10:15 and the observed spin direction of his curveball is 4:15. So, not only does his sinker add deception with his changeup, but it also adds deception with his curveball. His curveball has slightly below average vertical movement, but well above average horizontal movement which makes it another dangerous pitch if the hitter cannot identify it well enough.
Like with his changeup, Matz targets the bottom of the zone with his curveball. This makes it more effective with a high sinker. If Matz throws a high sinker, it will stay near the top of the zone. If he starts a curveball at the top of the zone, it will look like a sinker because of the opposite spin, but it will drop an extra 36 inches to the bottom of the zone. This deception allows Matz’s curveball to be extra effective and it is no wonder it is his primary breaking ball (he also throws a slider).
Matz’s curveball allowed a .299 wOBA and .255 xwOBA in 2021 with a 31.4% whiff rate.
The sinker is the foundation of Matz’s arsenal. It is the pitch that every other pitch is built on. Varying his location and throwing it high while his secondaries are generally thrown low, (but can also move up in the zone) allows him to add deception to his pitches and prevent hitters from keying in on one location. Throwing his sinker high allows his changeup and his curveball to have more success as they can start in the same zone but then drop much more than his sinker. Even though, Matz’s sinker was not the most successful pitch in 2021, he made up for it by having success with his secondaries. He is more effective with a sinker than he would be with a four-seamer because his sinker has more of a tilted spin axis which allows every other pitch to play up.
Matz is unique with the fact that he targets the upper parts of the zone with his sinker, but he does it for good reason. His arsenal is built on deception and this deception increases when he uses the upper part of the zone instead of ignoring it and keeping his pitches low like most sinkerballers. The St. Louis Cardinals would do well to leave this strategy alone and let Matz build off his strong 2021 season.