Pitch spin rates have been a focus in recent years, with evidence that fastballs with higher spin rates perform better than those with lower spin rates.
That’s a prominent topic today as baseball considers a crack down on sticky substances — potentially used by 90% of pitchers — that increase pitch spin rate.
You may remember that Royals fans targeted Richard Rodríguez in April for potentially storing a spin-enhancing substance on the inside of his glove. Perhaps not coincidentally, Rodríguez boasts the second best fastball spin rate on the Pirates.
At Performance Velocity Systems, a Pittsburgh-based baseball training center, Travis Sawchik recently tested the impact of foreign substances on spin rates. The results were startling.
Here’s a primer on what spin rate can do for a pitch, but in short, “balls that are thrown with the same velocity but different spin rates will end up in a different place from the pitcher’s hand to when they reach the catcher’s mitt.” If thrown with the right axis, a high spin-rate fastball will rise more than a low spin-rate pitch — and we know that vertical movement is an important trait. Higher spin rates can also help breaking balls move more.
Do fastballs with higher spin rates actually produce better in-game results? Thanks to several studies, including some data sleuthing over at Fangraphs, the answer appears to be a resounding yes. In fact, according to the article, “an increase in 100 rpms on the four-seam fastball increased the pitch’s run value by 0.2 runs per 100 pitches.”
Sawchik presented the following evidence: “Since the start of last season, batters are hitting .264 on four-seam fastballs that range from 2,250-2,350 rpm, a league-average range, and .217 against fastballs with greater than 2,500 rpm of spin.”
How do the Pirates’ spin rates compare to the rest of MLB?
We are still in the smallish sample size portion of the season, but you can see from the table below that the majority of the Pirate pitchers who have thrown 4-seam fastballs for the club this year have higher spin rates than the league average of 2,317, per Baseball Savant. Included are the number of 4-seam fastballs thrown so that you have an idea of sample size:
|Pitcher||4-Seam Fastballs||Average Spin Rate|
|Chase De Jong||91||2,529|
|Duane Underwood Jr.||195||2,143|
Is this an indication that foreign substances are prevalent in the Pirates’ clubhouse? Not necessarily. Some pitchers may have an innate ability to spin the ball better than most.
Spin rates are, though, hard to change, so big gains in RPMs may hint at an extracurricular activity. There are a handful of Pirates who have shown marked improvements in fastball spin rate in the last few years:
|Pitcher||2021 Spin Rate||Past Spin Rate||RPM Difference||% Difference|
|Chase De Jong||2,529||2,217||312||14.07%|
With baseball preparing to reduce the use of foreign substances on the mound, data hounds will be scrutinizing spin rate changes across baseball.
In addition to the Pirates listed above and these other notable spin rate gainers (including Tyler Glasnow), all eyes will be on guys like ex-Pirate Gerrit Cole, whose 4-seam fastball had a spin rate of 2,164 in his last season in Pittsburgh but now boasts a whopping 2,548 RPMs. As Trevor Bauer wrote, clearly targeting his long-time adversary: “I mean, when I see a guy go from being a good pitcher for one team and spinning the ball at 2,200 rpm, to spinning the ball at 2,600 or 2,700 in Houston, I know exactly what happened.”
Bauer continued: “I’ve been chasing spin rate since 2012. For eight years I’ve been trying to figure out how to increase the spin on my fastball because I’d identified it way back then as such a massive advantage. I knew that if I could learn to increase it through training and technique, it would be huge. But eight years later, I haven’t found any other way except using foreign substances.”
Like a few current and former Pirates, Bauer may not be in a position to throw stones, based on his own spike in spin rate.