Spin rates: MLB appears to have a possible cheating scandal on its hands again

Spin rate data paints a questionable picture about the status of foreign substances in the MLB this season.

Last week, New York Mets pitcher Max Scherzer was ejected and subsequently suspended for 10 games for what wound up being an illegal use of rosin. This comes just about two years removed from MLB’s “sticky stuff” scandal that led to pitcher hands, gloves, and uniforms being periodically inspected for unauthorized foreign substances that might give players a better grip on the ball, and an easier chance at creating spin (and thus movement) on pitches.

This chapter in the “sticky stuff” saga was made even more controversial on Sunday night when David Cone showed us just how sticky rosin can be when activated by something like an alcohol-based hand sanitizer.

Here’s what rosin is and an explainer on its legality in the game today.

Looking deeper at the data, it’s possible that the league has another cheating scandal on its hands that may or may not be related to this sneaky activation of rosin. I am not suggesting the following data is definitive proof of such a league-wide occurrence, but I am ready to admit that I’m openly skeptical this is just an anomaly.

Data acquired 4/24 for the first 24 days of the 2021, 2022, and 2023 MLB seasons. All data courtesy of Baseball Savant. 

MLB’s spin rate averages are up in 2023

The first thing to look at is average spin rates. I looked at the first 24 days of the last three seasons and compared the average spin rates across the league for six pitches. The truth is, the spin rates so far this season look a lot more like the first 24 days of 2021, the infamous spider tack season, than last year.

To wrap, the averages compared to 2022:

• Fastball: Up 24; 98.7% of 2021
• Changeup: Up 54; 98.7% of 2021
• Curveball: Up 31; 99.02% of 2021
• Cutter: Up 24; 99.67% of 2021
• Sinker: Up 35: 100.1% of 2021
• Slider: Up 12; 97.75% of 2021

While average spin rates are still not touching that of early 2021, clearly, the spin rate is back up so far this season. Again, we’re comparing the first 24 days of each year here, so factors like new techniques, fresh arms, etc. should more or less factor out.

MLB’s upper echelon of spin rates is also up

When looking at the subject of whether or not players are getting an unfair competitive advantage from something like a foreign substance, an average might not tell the whole story.

Not everyone is immoral enough to cheat or take up a loose interpretation of the rulebook. Only the few that decide to risk it — whether that be by using “true” sticky stuff or activated rosin — will see the benefits. For that reason, I think it’s important to also compare the 95th percentile this year to that of the previous two seasons.

Here, there’s a far less troublesome story being painted for every pitch except the curveball. The 95th percentile is still up from 2022, but much further away in several cases from 2021 than when we look at averages as a whole.

The curveball could be a legitimate concern, the 95th percentile reached this season is higher than we saw even at the start of 2021.

But again, this might not capture the entire story. Let’s look at individual pitchers.

Pitchers who have a drastically higher spin rate this year than last

There are a total of 40 pitchers this year who have at least two pitches in their arsenal that they are throwing with 4 percent or more spin this year through the first 24 days compared to the first 24 days of the 2021 season.

They are:

1. Lorenzen, Michael – 5 such pitches
2. Davies, Zach – 3 pitches
3. Dunning, Dane – 3 pitches
4. Eflin, Zach – 3 pitches
5. Graveman, Kendall – 3 pitches
6. Loup, Aaron – 3 pitches
7. Manning, Matt – 3 pitches
8. Martin, Chris – 3 pitches
9. Scherzer, Max – 3 pitches
10. Wheeler, Zack – 3 pitches
11. Wilson, Bryse – 3 pitches
12. Abreu, Bryan – 2 pitches
13. Alcala, Jorge – 2 pitches
14. Bruihl, Justin – 2 pitches
15. Burke, Brock – 2 pitches
16. Chapman, Aroldis – 2 pitches
17. Crawford, Kutter – 2 pitches
18. Falter, Bailey – 2 pitches
19. Feltner, Ryan – 2 pitches
20. Fulmer, Michael – 2 pitches
21. García, Yimi – 2 pitches
22. Gore, MacKenzie – 2 pitches
23. Hader, Josh – 2 pitches
24. Irvin, Cole – 2 pitches
25. Lamet, Dinelson – 2 pitches
26. López, Jorge – 2 pitches
27. López, Pablo – 2 pitches
28. López, Reynaldo – 2 pitches
29. Lugo, Seth – 2 pitches
30. Montgomery, Jordan – 2 pitches
31. Nola, Aaron – 2 pitches
32. Pop, Zach – 2 pitches
33. Raley, Brooks – 2 pitches
34. Schreiber, John – 2 pitches
35. Sims, Lucas – 2 pitches
36. Speier, Gabe – 2 pitches
37. Strahm, Matt – 2 pitches
38. Stratton, Chris – 2 pitches
39. Thompson, Keegan – 2 pitches
40. Whitlock, Garrett – 2 pitches

That’s not to say an appearance on this list is evidence of cheating or foul play. 4 percent is a low threshold, so depending on the pitch and player, this can amount to 60-150 of additional RPM.

Several of the players on this list could also appear due to low personal sample sizes, improved mechanics, or just simply better pitching. I have not filtered them for any such qualifiers. But it’s a long list, and while 4 percent might not seem like much, it can translate to a sizable increase in spin rate.

Perhaps most telling will be looking at players who have large numbers of individual pitches that are spinning faster in 2023 than they were in the first 24 days of the 2021 “sticky stuff” season, when spin rates were supposedly “out of control” at an unprecedented level.

Those are as follows:

1. Turnbull, Spencer – 5 such pitches
2. Wheeler, Zach – 5 pitches
3. Civale Aaron – 4 pitches
4. Davies, Zach – 4 pitches
5. Dunning, Dane – 4 pitches
6. Eflin, Zach – 4 pitches
7. Fulmer, Michael – 4 pitches
8. Garcia, Luis – 4 pitches
9. Kelly, Merrill – 4 pitches
10. Nola, Aaron – 4 pitches
11. Payamps, Joel – 4 pitches
12. Romero, JoJo – 4 pitches
13. Woodford, Jake – 4 pitches
14. Abreu, Albert – 3 pitches
15. Abreu, Bryan – 3 pitches
16. Alcala, Jorge – 3 pitches
17. Alexander, Scott – 3 pitches
18. Barlow, Scott – 3 pitches
19. Cisnero, Jose – 3 pitches
20. Crismatt, Nabil – 3 pitches
21. deGrom, Jacob – 3 pitches
22. Fleming, Josh – 3 pitches
23. German, Domingo – 3 pitches
24. Gray, Jon – 3 pitches
25. Gray, Jon – 3 pitches
26. Hicks, Jordan – 3 pitches
27. Keller, Mitch – 3 pitches
28. Kremer, Dean – 3 pitches
29. Lopez, Jorge – 3 pitches
30. Lopez, Pablo – 3 pitches
31. Maeda, Kenta – 3 pitches
32. Maton, Phil – 3 pitches
33. May, Dustin – 3 pitches
34. Montgomery, Jordan – 3 pitches
35. Neris, Hector – 3 pitches
36. Peralta, Freddy – 3 pitches
37. Peterson, David – 3 pitches
38. Plesac, Zach – 3 pitches
39. Rodriguez, Eduardo – 3 pitches
40. Tepera, Ryan – 3 pitches
41. Weathers, Ryan – 3 pitches
42. Wells, Tyler – 3 pitches
43. Wilson, Bryse – 3 pitches

Here are some egregious examples.

• Dinelson Lamet’s slider has increased from 2410 to 2616 (run value of +1, equal to last season)
• Dane Dunning’s slider has increased from 2081 to 2443 (run value of 0, an improvement of -5 from last season)
• Matt Manning’s sinker has increased from 1931 to 2120 (run value of +1, a decline of +2 from last season)

Scherzer is another obvious place to look to start. His curveball is achieving 58 more rpm this season than last (+2 worse run value), and his cutter 97 more (-3 better run value).

Scherzer’s former teammate Jacob deGrom is having an outstanding season with the Rangers. His fastball is up 35 over 2021, and his slider is up 73. Both are higher marks than he reached on those pitches in 2021, as illustrated in the list above.

Domingo German shows up on the list of pitchers that have two pitches spinning faster than in 2021. His curveball was spinning 2,624 RPM in the first 24 days of 2021; It’s spinning at 2,719 through the first 24 days of this season. His fastball was 2,466 at this stage in 2022; It’s spinning at 2,530 this season so far. Before Scherzer, German was the subject of cheating accusations earlier this season.

Jordan Montgomery of the St. Louis Cardinals has a drastic 149 jump in spin rate on his curveball. That pitch has not performed well in 2023, with a +6 worse run value.

Aroldis Chapman is bouncing back with the Kansas City Royals. His fastball compared to last year is 175 higher (career high), his slider 120 higher, his split-finger 592 higher (career high), and his sinker 67 higher. Each of those pitches has a run value equal to or better than last year, when Chapman missed plenty of time and otherwise struggled mightily.

In all, these numbers don’t prove anything. But they speak a pretty loud, known truth: The MLB has some sort of anomaly going on with its pitching that is producing spin rates even higher than its controversial 2021 start of the year.

Those spin rates were enough to get the league to intervene in 2021. Will they do the same this year? Maybe Scherzer’s suspension was enough of a statement. But maybe it wasn’t.

Whether this anomaly is due to differences in baseballs compared to previous years, unauthorized or authorized substances on pitchers’ hands, or something else altogether is yet to be figured out.