Alec Mills threw the game of his life on September 13th, 2020. That day, the right-hander authored the 17th no-hitter in Cubs history. Through his nine frames, zero batters tallied a hit against the Cubs' righty. Despite coming into the game with a 4.74 ERA on the season, Mills masterfully worked his way through Milwaukee's lineup, inducing ten ground ball outs.
Craig Edwards of Fangraphs described Mills' no-hitter as the luckiest such feat in the Statcast Era. Based on the BBEs of the game, Mills' no-no had a probability of a 0.01% of happening. That's not to discount Mills' pitching; he's certainly an interesting arm.
He might not be a household name, or even one you would roster on your fantasy roster, but he does have a couple of unique, defining traits. He’s certainly not a power pitcher, rather a sum-of-the-parts-equals-more-than-the-whole; a phrase that defines the Cubs' approach to starting pitching, as a whole, this season.
He’s limited barrels extremely well this season and I suppose that makes sense. Sinkerballers, such as Mills, throw pitches designed to induce ground balls. An increased GB% is one of the limitations of expected stats, a subject that I’ve previously touched on.
In his article introducing Baseball Savant’s new Spin Direction tool, Mike Petriello of MLB.com noted four pitchers whose fastball spin mirrors the spin of two of their offspeed pitches: Shane Bieber, Lance Lynn, Luke Jackson and Alec Mills.
Two of those names I expected to see: Bieber's the reigning Cy Young Award winner and Lynn's riding a late career resurgence as a favorite to this year's honor. But Mills? Aside from the aforementioned no-hitter, there hasn't been much noise surrounding the Cubs' right-hander.
Despite a career 4.34 ERA/4.38 FIP, I'm intrigued about Mills. Petriello's mention of him in his Spin Direction article was enough to go down the research rabbit hole and I'm glad I did.
Take a look at this recent overlay by the masterful PitchingNinja.
https://twitter.com/PitchingNinja/status/1397974573249925126
Here's what the pitches look like in BallR
https://videopress.com/v/UFtdLdNh?autoPlay=true&loop=true&preloadContent=metadata
As we can see from the BallR visualization above, Bieber's pitches look like they’re spinning on the same axis. However, one is thrown with topspin and the other, backspin. The pairing of topspin and backspin on consecutive pitches make it more difficult for a hitter to pick up on a pitch's late movement. Bieber rode this deception en route to his 2020 Cy Young award.
Baseball Savant shows that there's approximately a six-hour difference between the release of the two pitches.
To the hitter, it makes it harder to pick up which pitch is which. One of the only giveaways between the two offerings is the direction the seams are going, which is incredibly difficult to pick up considering the velocity of the pitch.
Mets’ minor-leaguer Josh Hejka was kind enough to write about this effect, both for his personal blog and for MetsMerizedOnline.com. Hejka, a sidearming reliever in the Mets’ farm system, strives for that approximate six-hour gap between his fastball and his slider. But, since he’s a sidewinder, Hejka doesn’t release his fastball at the conventional 12:30 axis. Instead, his fastball is released at 3:00, with his slider being released around 9:30, as of 2020. This approximate 6:30 hour gap in spin axis gives the appearance of his pitches tunneling together, before one yanks to the left and the other right.
https://twitter.com/joshhejka/status/1256724327774531589?lang=en
Mills, while not a sidearming reliever like Hejka, faces a similar conundrum with his repertoire. His axis isn't optimized, but there is still a six-hour mirror between his fastball, slider and curveball. To add to Mills' credit, he throws not only one pitch that pairs with his fastball; he throws two! Per Savant, his fastball is released at 1:30, his curveball at 7:30, and his slider at 7:45.
Here's how his pitches look in BallR.
https://videopress.com/v/xDrZ4t0G?autoPlay=true&loop=true&preloadContent=metadata
Although there's a six-hour gap between three of his pitches, he hasn't enjoyed the same success as Bieber or Lynn.
Since he releases his fastball from more of a three-quarter slot, his delivery isn't optimized. It's not an overpowering pitch; rather it's another pitch that lives down in the zone. Nor is it velocity-driven; it's one of the softer fastballs in the game, a trait that many sinkerballers share.
He doesn't throw his fastball often either, relying more on his sinker, hence his reputation as a sinkerballer. His batted-ball profile certainly agrees with that assessment; his 58.5% ground ball rate is 13% above the league average of 45%.
But since he doesn't elevate his fastball often, the six-hour difference between his fastball, slider and curveball has a lesser effect.
His pairing is great, but it’s combined with a poor profile. A fastball/curveball/slider with optimal spin directions should generate an above-average amount of whiffs. But with a profile that’s optimized to induce ground balls and an arsenal that emphasizes his sinker, it’s a trait that doesn't help considering the entirety of his profile.
Cover Photo: Sporting News