Stop me if you’ve heard this before.
Jose Berrios entered 2017 with his career arc somewhat in doubt. Formerly a top prospect, he’d struggled—no, he had outright failed—in his first extended look in the majors, and despite his youth and his raw stuff, even his most enthusiastic supporters were forced to admit that big changes were needed if he was going to turn himself into a valuable big-league hurler.
Happily, though, he’s made precisely those changes this year. He’s lowered his arm slot slightly, and moved to the third-base side of the rubber. His adjustments are a little more complicated than that simple summary suggests, but the gist is accurate, and the results have been everything for which one could hope. Berrios’ average spin rate on his fastball is up 114 RPM this year. There’s been a much smaller increase in spin rate on his curveball, but the pitch has had much better tilt this season, so it’s still improved.
Batters are whiffing far more often on both pitches this year, and exit velocities against both pitches (plus Berrios’ changeup) are way down. He’s getting ground balls with his curveball and pop-ups with his fastball, and he seems to be easily throwing more strikes, too.
Wait. You didn’t stop me.
This should sound familiar by now. It’s a variation on the themes I sounded in pieces on Brad Peacock and James Paxton earlier this month. While there’s no particular way to train spin rate—to increase a pitcher’s spin through simple drills or conditioning—a common thread is beginning to tie these stories closely together. Lower arm slots just seem to be more natural for some pitchers, and changing to them seems to permit those hurlers’ arms to work more efficiently and naturally.
If you’ve heard the old scout’s saw about being a Ferris wheel, rather than a merry-go-round, you know that conventional wisdom has long favored pitchers who throw more or less over the top versus those who employ a lower arm angle. The more we learn, though, the less that old standby seems worth standing by. That insight is not new, or close to new. Former BP pitching guru Doug Thorburn wrote brilliantly about the problems with traditional assumptions about arm angles and creating downhill plane, and about how some organizations let pitchers find their own optimal arm slot, while others (perhaps foolishly) mandate that their guys use certain mechanical patterns to get on top of the ball and generate tough angles for batters.
Thorburn spoke specifically to Berrios’ brutal 2016 on his podcast Baseballholics Anonymous last month. He said that most of Berrios’ problems last year stemmed from alignment—that his delivery almost aimed at the right-handed batter’s box, giving him no chance to consistently throw strikes or execute his secondary stuff. It would seem that moving across the rubber has helped Berrios fix that issue this season. He’s also had what Thorburn would call better posture this year—his spine is less tilted at release, and he finishes with power and balance, even though he still appears to fall off toward first base at times. Former MLB pitching coach Rick Peterson talks with some frequency about maintaining strength in the landing leg; Berrios has done that better this year, too.
One thing Thorburn never does is speak in unmitigated generalities. Not every pitcher should throw any one way. It would seem, though, that there are more pitchers who have been coached into throwing at a higher arm slot than is natural for them than there are who have been coached into throwing from too low an angle. It does make it marginally harder for opposite-handed batters when a pitcher throws from a high angle, but if that pitcher would naturally throw from a lower slot, he probably should.
Whatever is lost, in terms of deception, can be gained back in the areas of consistent execution, command, and health. In the cases of Peacock, Paxton, and Berrios (these aren’t the only examples; they’re just the ones I’m using to illustrate the point), throwing more naturally has allowed them to spin the ball better (on both their fastballs and their breaking stuff) and to control their natural movement better.
Cubs left-hander Mike Montgomery is an interesting counterexample, at least for now. He’s a former teammate of Paxton’s, with a good fastball (it can work into the mid-90s even now that he’s in the rotation) and a devastating breaking ball, plus a decent changeup and a usable cutter. He really struggles to consistently command the ball, though. He also has a very, very low spin rate on his fastball. Amir Garrett of the Reds shares these traits. The list of guys who (given what we’ve seen from pitchers like Peacock, Paxton, and Berrios this year) should at least consider lowering their arm slot is pretty long.
It might very well be that this isn’t the secret, even for these three pitchers (though all three say they feel much more comfortable throwing this way). It doesn’t seem to be something anyone is eager to do on a broad scale, perhaps because it does figure to make anyone who does it slightly more vulnerable to platoons. Still, any pitching coach or front office executive will tell you that a good potential starter needs a repeatable delivery and fastball command. Mounting evidence suggests that finding a natural, lower arm slot could help many pitchers check those boxes.
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