Being a major league pitcher isn't the sweet gig that it used to be. You can't use sticky stuff. You can't take your time. Heck, you can't even rely on over-shifted defenders and small bases to save your bacon in a pinch.

But for all the things Major League Baseball can change, it will never be able to outlaw filthy pitches.

So, let's look at the filthiest of them all through the first month of the 2023 season. These are pitches that not only look the part, but which also trafficking in various forms of statistical dominance. In other words, they're about as unhittable as they look.

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We have one selection for each pitch type, amounting to a total of nine. And while we will be giving honorable mentions to relief pitchers along the way, we gave the nine spotlights to starting pitchers for sample size purposes.

As always, we owe a special thank you to Rob "Pitching Ninja" Friedman for GIFs and videos.

Note: All stats are current through games on Sunday, April 23.

 

Luis Castillo's Four-Seam Fastball

  • Key Stat: Its 43 whiffs lead all four-seam fastballs.

Luis Castillo loves his four-seam fastball and, really, why shouldn't he?

The Seattle Mariners ace actually threw his four-seamer less often than his changeup between 2019 and 2021, but now it's easily his primary offering and drawing whiffs on 39.1 percent of the swings against it. That's a career high.

This might seem counterintuitive in context of how Castillo's average velocity is down to a career-low 95.0 mph, but that isn't the best metric for understanding his heater.

It's better to consult vertical approach angle, which quantifies the angle at which a pitch approaches home plate. A four-seamer with a VAA close to zero degrees is considered "flat." In a good way, that is. It effectively travels the shortest distance between its release and its target, which is ideal for a pitch that's meant to beat hitters with speed.

Per Alex Chamberlain's custom leaderboard at Tableau, the VAA on Castillo's four-seamer (minus-4.0 degrees) is closer to zero than that of the average hurler (minus-4.8 degrees). If it feels like his fastball teleports to the catcher's mitt, that's why.

Honorable Mention: Jacob deGrom, Texas Rangers

 

Dustin May's Sinker

  • Key Stat: Its 75.0 ground-ball percentage is tied for first (min. 20 batted balls) among sinkers.

The spotlight here should probably belong to Josh Hader's sinker. It is, after all, limiting opposing batters to an .071 average and a .101 expected average.

But to be frank, Hader's sinker is kinda-sorta a fake one. And besides, it doesn't have the aesthetically pleasing arm-side run that the Los Angeles Dodgers' Dustin May gets on his sinker.

Not many pitchers pair that kind of movement with that kind of velocity when they throw their sinkers. It's really just May, Castillo (is there anything he can't do?) and Sandy Alcantara among right-handers who've thrown at least 100 sinkers.

It's therefore surprising that May has relegated his sinker to his secondary fastball in deference to his four-seamer. He's even throwing it higher in the zone, which is another one of those seemingly counterintuitive things.

But knowing that May also throws his four-seamer up in the zone, the idea seems to be to dare hitters to differentiate the two pitches before they behave differently upon reaching the hitting zone. As hitters are just 4-for-27 against May's sinker, the ruse is working.

Honorable Mention: Logan Webb, San Francisco Giants