Spin Doctors: the teams that have added the most fastball spin

Last week, Stephanie Apstein and Alex Prewitt wrote about the increase in foreign substances at Sports Illustrated. They identified LA as having the largest year-to-year increase in spin rate on four-seam fastballs, but looking at overall team average spin is somewhat misleading. As Apstein and Prewitt pointed out, the increases could be due to a change in personnel. Leaguewide spin rates are going up not just because of foreign substances but because teams are selecting for higher spin pitchers, so it makes sense that teamwide spin rate would go up for the same reason.

It’s more instructive to look at individual changes in spin rate, so what I’ve done is I’ve looked at every pitcher who has thrown at least 10 four-seam fastballs in each of the last two seasons and grouped them by what team they are currently playing for. In the case of free agents, I lumped them in with the last team they played with. I found 417 pitchers who fit this description. The question I wanted to answer wasn’t “who added the most spin to their roster” but “who was the most successful at increasing the spin of their pitchers.”

The point of this isn’t to identify teams that are encouraging the use of foreign substances to boost spin rates. Nothing that follows is proof that any of the teams or players mentioned are or are not using boiled down Pepsi or Spider Tack or pine tar to give themselves an unfair advantage.

For the players who haven’t seen big jumps in their spin rates, it doesn’t mean that they’re innocent. We’re only looking at changes from 2020 to 2021, so this will miss players who started using something before then or have been using something their entire big league careers. These are the players who have been grandfathered in, so to speak.

As for those who have seen big jumps in spin rates, there could be another explanation. It could be a change in grip or in mechanics. Maybe they weren’t 100 percent healthy last year. Just because the most obvious explanation is that they’re using sticky stuff, it doesn’t mean that we should jump to that conclusion. It’s not my job to identify those who are breaking the rules. It’s MLB’s.

Because this is only looking at pitchers who appeared in the each of the last two seasons, this ignores the many pitchers who missed 2020 entirely because they were hurt or they opted out. Going back to the Dodgers, this means that Jimmy Nelson and David Price aren’t included. It also misses primarily sinker and cutter pitchers like Nate Jones and Kenley Jansen. I wrote last week about the massive increase in Jansen’s spin rates. Jones, on the other hand, has seen a decrease in spin from last year. I don’t mean to pick on the Dodgers specifically, but they weren’t at the top of my leaderboards and I didn’t want to seem as if I was refuting what SI had found.

Below is the average change in four-seam spin for individuals in the organization.

Data Courtesy of Baseball Savant

The Dodgers aren’t on top, which is surprising but not nearly as surprising as the team in front of them. The Pirates have seen five pitchers with increases of 100 rpm or more on their fastballs: Wil Crowe, Kyle Keller, Chase DeJong, Tyler Anderson, and Chad Kuhl. Keller and Crowe have the two largest gains in spin from 2020 to 2021 of any of the pitchers included. Crowe’s average fastball spin rose 202 rpm, which brings him into the 83rd percentile. Keller’s rose 233 rpm, giving him 2.3 more inches of rise on his four-seamer. The high spin hasn’t done them any favors though. Both Keller and Crowe have ERAs over 7.00 and the Pirates pitching staff as a whole is seventh-worst by ERA and FIP.

Average gain in spin is somewhat misleading because pitchers like Keller and Crowe can skew things fairly heavily. Here’s the same chart again, but this time we’re looking at median gain in fastball spin.

Data Courtesy of Baseball Savant

This makes a little more sense. The Pirates are still in the top five but have been dragged down by the slough of pitchers who have only seen slight gains or losses. The Dodgers are still in the second spot, leap-frogged by the rival Padres.

Joe Musgrove is the lone Padre to see a jump of 100 rpm or more, but the staff has consistently added spin.

I could include tables for the other 28 teams, but that would get unruly. Instead, here are three charts showing individual changes in four-seam fastball spin from 2020 to 2021 grouped by teams. Here are the 10 best teams by average fastball spin increase.

Data Courtesy Baseball Savant

The Angels are pretty well represented with Shohei Ohtani, Mitch White, and Patrick Sandoval all seeing gains of 150 rpm or more. Los Angeles has nearly as many pitchers who lost spin, however. As Sports Illustrated found, the Dodgers are the most consistent gainers. The only three pitchers to lose spin are Dustin May, Joe Kelly, and Blake Treinen. Walker Buehler, Trevor Bauer, Clayton Kershaw, and Julio Urías all added spin despite having exceptional spin rates to begin with.

Data Courtesy of Baseball Savant

The middle 10 teams are, well, middling. The Rockies had two standouts: Mychal Givens and Antonio Santos. Givens’ spin rate jumped 150 rpm exactly, launching him from the 80th percentile to the 94th. Oddly enough, Givens has been throwing his four-seamer about half as often and replacing it with the changeup. Santos was a low-spin pitcher to begin with so another 130 rpm only brought him up to 2144.

Data Courtesy of Baseball Savant

Only two of the Phillies, Zack Wheeler and Sam Coonrod, have higher spin rates this year than the year before. Everyone else has lost a decent amount but no one quite to the degree of Toronto’s Nate Pearson or Arizona’s Taylor Widener. I know I said this doesn’t prove anything about who is and isn’t using foreign substances, but I’m going to wager that Philadelphia isn’t the team who hired a chemist to concoct sticky stuff for their pitchers.

So, there’s a quick and dirty look at which teams most successfully added fastball spin over the offseason. It, of course, wasn’t just the Dodgers who got more rpm out of their pitchers than the year before. More than half of the teams managed to squeeze more spin out of their pitchers than the year before. It’s not just that teams are selecting for more spin, they’re creating more of it, too.

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Kenny Kelly is the managing editor of Beyond the Box Score.