A look at Steven Matz's new pitch: the devastating Warthen slider

Steven Matz is throwing a new pitch, and it's a unique pitch that you may have heard of before. The famous "Warthen Slider" has entered Matz's repertoire. Matz joins some notable teammates in picking up the pitch at the big league level. Matt Harvey's breakout upon his promotion to MLB in 2012 was fueled partially by the new slider. Jacob deGrom, Jeurys Familia, and to a lesser degree Noah Syndergaard are some of the other high octane arms that have had fantastic results with the Warthen slider; opposing hitters have had a very difficult time doing anything against it:

Matz's usage of the pitch hasn't been on the level of a deGrom or Harvey, though, at least not yet. According to Brooks Baseball's pitch fx database, Matz has only thrown the pitch 11 times (5.6%) in 2 starts since debuting it, so the pitch is still in its infancy. deGrom and Harvey throw their sliders about 16% of the time. Notably, all of Matz's sliders have been thrown to left handed hitters to this point.

Matz began throwing the slider in his start against the Yankees on September 18, where he threw it 7 times, averaging about 87 mph with it. Matz told the media after the start that he had been working on the pitch in bullpen sessions with Warthen, and catcher Travis d'Arnaud raved about the pitch:

"It's pretty devastating...I'm glad I don't have to be in the box."

Greg Bird (three times) was the first to see the new Matz slider, followed by Brett Gardner (twice), and Didi Gregorius (twice).

Getting Brett Gardner to look at an 87 mph slider:

And a look at the spin from a side angle:

This is the first Warthen slider that Matz threw, an 88 mph slider to Greg Bird that was captured from a behind the plate view:

In his latest start against the Reds, Matz threw the pitch 4 times. But interestingly, the first 3 of them were to Joey Votto, the Reds most dangerous left handed hitter, and it accounted for 33% of all the pitches Votto saw from Matz in the start. The other one was thrown to LHB Jay Bruce. Matz seemed to be saving the pitch for potent lefty batters.

Matz freezing Votto with a 1-1 slider to get ahead 1-2:

Votto flinches at the pitch and backs away, indicating he was not expecting the pitch to move the way it did.

In Votto's next at bat against Matz, Matz attempted to get Votto to chase an 89 mph slider on the first pitch of the at bat:

Matz doubled up Votto with the slider on the second pitch. Votto generated a good line drive trajectory, but the pitch was executed in such a way that it either missed the sweet spot of the bat or threw off Votto's timing just enough to avoid Votto getting a lot of force behind it; Votto's exit velocity on the ball was 86 mph, which is below MLB average.

Matz already had a mid 90s fastball with movement, combined with a good curve, good change up and some delivery deception, which is nasty enough to have a large amount of success in the big leagues. But now that the Warthen Slider has made it's way into his pitch arsenal, Matz is in the middle of developing another weapon to attack hitters with, creating new ways for him to get opponents out and prevent runs. If the pitch develops the way deGrom's slider and Harvey's slider has, Matz could take another step forward at the big league level, which would make him an even more valuable pitcher going forward.