Given baseball's rich history of doctoring its namesake item, I don't expect Major League Baseball's new policy on grip-enhancers to end the practice.
However, we can tie up at least one loose end of our discussion on Monday. You may remember that Shane Bieber was the latest high-profile pitcher to suffer a big drop in spin rate during his thoroughly mortal outing against the Mariners on Sunday.
Perhaps the absence of some kind of foreign substance played a part, but another reason for his ineffectiveness emerged when Cleveland placed him on the 10-day injured list with a right shoulder subscapularis muscle strain. He'll be shut down for at least two weeks, after which he'll be re-evaluated.
It's similar to the big drop in spin rate that Lance Lynn experienced around his bout with back tightness in April, so it speaks to at least one factor that hampers that metric independent of the current furor.
Speaking of which, Lynn had to battle through six innings against the Rays, giving up a pair of homers. If you look at the Game Feed on Baseball Savant, you can see that his fastball spin rate also dropped by triple digits.
But when you look at his season-long chart, is it the kind of dip that looks meaningful? Not really, unless there's more of a slide to follow.
As it stands, his spin rate changes are still around one standard deviation of normal. In a useful article for The Athletic, Eno Sarris and Britt Ghiroli said that pitchers can fluctuate 115 rpm or so over the course of a season, so one might have to double that margin to find a serious offender.
There appears to be a kind of cumulative cooling effect, but it's going to take more evidence to isolate genuine spin rate issues from other things that muddy up month-over-month comparisons, because offenses usually jump in production around this time of year regardless. For the time being, I just want to understand what I may be seeing when I see a sizable shift in spin rate, most notably what qualifies as "sizable." So there's at least a little bit of progress on that front.
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Speaking of MLB's new midseason policy, the enhanced enforcement will begin on Monday, and as you might expect from any guidelines presented in the middle of a summer without input from the players, it's a mix of sensible, confusing, and susceptible to loopholes.
MLB.com's Anthony Castrovince has probably the most straightforward summary of the rules:
Under the new guidelines, any pitcher who possesses or applies foreign substances in violation of the rules will be ejected from the game and automatically suspended in accordance with the rules and past precedent. Suspensions under Rule 3.01 are 10 games. Starting pitchers will have more than one mandatory check per game, and relievers must be checked at the end of the inning when they entered the game or when they are taken out of the game, whichever comes first. Typically, the inspections will take place between innings or during pitching changes to give the umpires ample time to perform a thorough check without delaying the game.
Players will be paid during suspensions for this violation; repeat offenders will be subject to progressive discipline. Clubs and club personnel will also be subject to discipline for failure to ensure compliance with these rules.
This purports to crack down on substances all the way down to the generally accepted combo of sunscreen and rosin, with the league advising pitchers to avoid personal applications in situations it doesn't apply (games at night or with a closed roof). They also attempt to limit gamesmanship from managers, but it's inviting Tony La Russa to put his law degree to use:
As always, it'll come down to consistency of enforcement, and the ability for umpires to actually know what they're looking at when they assess things like fingertips. It doesn't seem likely to act as a deterrent if it doesn't result in at least a couple of notable suspensions. The one part I do like? Any pitcher who is suspended can't be replaced on the roster, which provides additional incentive for teams to police their own actions. It just can't rely on peer pressure to see it through, because we've seen how little that does.
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There was another loose end from Monday's White Sox action that didn't pertain to foreign substances -- Tyler Glasnow's premature exit after four innings. The Rays had to brace for the worst given the way Glasnow was favoring his forearm, and while they've avoided the biggest possible blow, the news isn't good:
The Rays placed Glasnow on the injured list, and called up infielder Mike Brosseau to take his place.
UPDATE: Glasnow says his injury is related to the above topic after all:
(Photo by Erik Drost)
