With some claiming that 80% of pitchers used some sort of a tacky substance, with some 10% using SpiderTack-level stuff, the notice came around in June with an actual enforcement of Rule 6.02.
Here’s the outcome:
Spin Rate Changes
I pulled Fourseam Fastball data from BaseballSavant, setting the date pre- June 13th, and post- June 20th(to July 8th). I didn’t count the week in-between as not everyone took off by the 20th.
The lower ranges of spin rates didn’t budge, while the upper range did.
At this point, it’s almost safe to assume that a consistent >2600RPM is naturally unsustainable. One could even argue that number to be 2400RPM of transverse spin since cutting the ball increases spin rate.
The change in Vertical Movement distributions isn’t as clear as the spin rate changes, since they’re obviously not 100% correlated, and the actual movement of the pitch is dependent on more factors.
But the pattern remains the same: highest V.Mov. pitches are gone.
There have been studies that found increases in velocity with the use of sticky substances; the few extra milliseconds on the ball allow extra time for the fingers to apply force behind the ball.
The actual pitch velocities don’t seem to support that:
- Average velocity pre- June 13th: 93.75mph
- Average velocity post-June 20th: 93.69mph
There indeed was a decrease, but a difference of 0.06mph is negligible.
Many pitchers didn’t go cold-turkey right away, likely because of the injury risk; loss of friction requires extra grip(extra work by the forearm) which can cause strain on the elbow that’s already handling absurd levels of torque.
Pitchers can instead gradually reduce the stickiness of the substances and not have such a drastic change on the body.
Despite all the criticisms of the enforcements, I think it was a net positive.
It clearly levelled the playing field by keeping the players from having an unfair advantage: A. Improving Fourseamers but not Sinkers, and B. Having better substance than others.
Baseball, as a sport, shouldn’t be a game of “who has better technology” but a game of “who’s better at actually playing the sport”.
The spin rate issue was something that was destined to be addressed, and we should celebrate that the MLB has actually taken action to make the game better.
Regaining Spin Rates?
There’s been a strange phenomenon with some pitchers: recovering spin rates back up.
22 Pitchers have gained more than 100RPM on their Fourseamers after the enforcement.
It’s unclear why, while the potential reasons are:
- They found ways to hide sticky substances
- Their forearms adjusted to the loss of friction–forearm strain leads to spin rate loss–by improving active forearm strength
The latter is a lot more likely, although it brings the question of “why did they use the substance in the first place”, or “are the effects of sticky substances less than advertised”.