Pitcher ratings: sticky item ban memo

Note: During the All-Star hiatus, at least Paul and I are going to break down the pitching results and they will all be in this article for easy reference. The article will grow throughout the week as more and more reports are written. Please submit any pitchers recommendations in the comments making sure they are only actionable launchers (not Cole or Giolito).

Background

For those returning from a two-year underwater tour, here’s some information on the current state of the sticky ban. Pitchers who use sticky stuff on baseballs create more spin and more spin can result in more strikeouts for some pitches. Someone (s) felt it was finally important to start enforcing the rule after decades of closing their eyes. Here is the repression calendar.

• April 1: Bullets were collected which were believed to contain sticky stuff.
• May 15: The turnover rate across the league has plummeted. It almost seemed that the teams had received a double secret memo before the official memo.

The crackdown on sticky stuff has only produced an absolutely insane reduction in turnover rates across the league. We really don’t have a good historical parallel as to how low the RPMs will be, but this change will reduce the K% and dramatically increase the runs. https://t.co/c5ST8JF3t0 pic.twitter.com/k98ASf223q

– Rob Arthur (@No_Little_Plans) June 25, 2021

• June 15: an official MLB memo came out indicating that the referees were going to start cracking down (leaked on the 14th).
• June 21: The referees started checking the pitchers.

So there was roughly a month and a half of pitchers doing whatever they wanted. A month when everyone knew that a repression was coming. And this last month of being checked at each round.

Once the crackdown was about to take place, several people wrote about the potential effects. Athletic noted that the shots that would see the greatest effect of having less spin would be the fastballs and the four-seam sliders.

Also, we are only focusing on the four seams and sliders because, as you can see in this image, the effect of the rotation on the shrinkage rate for beaters ending in a four seam and a slider is severely affected by the amount of rotation. is on the ball.

The relationship isn’t particularly strong in terms of predictability – there’s a lot more to the effectiveness of a pitch than just the turnover rate – but there is a relationship here that matters.

The same article specified that the average drop in the withdrawal rate would be 1%. In another Athletic post, Eno Sarris explained a few reasons pitchers might not have as much difficulty as originally expected.

On the one hand, you see in Codify’s tweet above that the speed has increased a bit while the spin is going down. It could be that the pitchers make up for the lack of spin by throwing harder, it could be that time just leads to faster, faster balls, it could be that without a gooey substance shooting the ball more energy will be putting straight into the fastball, or it could be a combination of some of these factors. Either way, faster fastballs work better – the hit percentage this year on a fastball between 92 and 93 is 0.500, and it drops to 0.445 on balls thrown between 94 and 95 – so that could cancel part of the effect of the effect removal.

There is also evidence that at least some pitchers are moving away from the four seams and pitching more than two seams recently, which points to the specter of in-game type adjustments. Perhaps some pitchers vary the location of the pitch more. their fastball, or their mix of terrain, or their speeds – a lot of those things won’t be covered in a league-wide assessment, but they could introduce some noise into the league results.

Simply, the MLB has been trying to crack down since the start of the season, the spin is down, but overall the results have not changed.

Pitchers

Dylan ceases

While Cease hasn’t been the best since the crackdown, the only obvious difference between before and after is his home run rate.

His strikeout and goal are effectively unchanged and his xFIP is down due to more balls on the ground.

One small change is the increased use of the curve ball. The increased usage may have masked the fact that his fastball and slider performed less well as their spin rates plummeted.

It was almost as if the White Sox management and Cease had a pre-application plan to keep production going. The change might not have been noticeable had it not been for home run regression. -Jeff

Alex cobb

Just when the ban seemed inevitable (coincidence?), Cobb went to the IL with a blister on his finger. Here is his performance divided by pre-injury, post-run injury and post-run.

He’s come back after the bulb throwing his splitter fewer times, and his batting takedown rate is the batting takedown rate he suffered. Since becoming healthy he has a 3.63 ERA and has even matched his under 3.00 ERA in recent starts.

As noted in the Background section, the results of the sinkers and separators will not be as affected by a lack of sticky substance, although it appears Cobb was using some of it due to the lower turnover rates.

Simply, it looks like Cobb is finally healthy and the results have improved. -Jeff

Tarik Skubal

Skubal is having an interesting season and the possible changes in sticky stuff have nothing to do with it. The changes revolve around the adjustments in his pitch mix. In May, he dropped his splitter (10% SwStr%) and went back to his money (17% SwStr%). Then in June, he started throwing a lead (8% SwStr%, 50% GB%). Here are its uses of the pitch and its results during each period.

With the addition of the lead, he traded strikeouts for balls on the ground.

Watching his throws, there are definite pauses when his spin has dropped. They weren’t on the same day, which seems to match her constant tinkering this season.

Although it has lost a bit of spin, both throws work the same or better. As Skubal’s rotation has plummeted, his pitch mix changes explain his season from top to bottom. -Jeff