What Domingo German’s spin rate says about cheating, explained

On Saturday afternoon, Minnesota Twins manager Rocco Baldelli was ejected just before the start of the fourth inning. Just before, umpires had crowded around Yankees pitcher Domingo German, the subject of a hand and glove inspection for “sticky stuff” that may or may not have been impacting his success that day.

German had retired 9 batters at that point, throwing a so-far perfect game. It was a noticeable improvement from his first two starts. German had an ERA of 5.87 coming into the day.

In the end, umpires explained that there was a substance on German’s hands. An accepted explanation was that it was rosin, an approved substance. Umpires asked German to wash his hands at the end of his appearance in the third inning, and they reinvestigated at the start of the fourth. Some leftover substance on his pinky was the subject of the search, and umpires conferred.

Ultimately, German was allowed to pitch on, which is what got Baldelli upset.

In the ensuing hours, the debate over whether or not German cheated came into discussion. On one side, fans felt that if there was any substance worth deeper investigation, he had bent the rules too much. On the other side, fans felt it was a whole lot of nothing.

Then, there were the nerds (I will proclaim myself part of that group) who took to the breadth of data available at our disposal that the MLB tracks. Spin rate on German’s pitches came into question, with drops before and after the hand wash talk coming into view.

So, what does all that mean?

For your convenience, if you’re only interested in a certain part of this conversation, you can click through on any of these links to see different parts of the discussion. Otherwise, read on through as normal.

Spin rate could be due to fatigue | Best stuff all year cheating proof? | Pitch movement explains more

Theory: Spin rate doesn’t matter

I saw this argument thrown out by angry fans a lot on Saturday that spin rate, “doesn’t matter.”

The idea behind this argument is that spin rate is a big number, often a little too abstract for us to completely internalize. A ball clocking at over 2,000 “RPMs” sounds like a lot, but when we sit and think about what RPM is (revolutions per minute), it feels more small potatoes.

Consider that the average pitch happens in less than a second, and even a few hundred RPM added to a ball only adds a fraction of a rotation on the ball per pitch.

That said, this stat absolutely matters, if it didn’t, it wouldn’t be something the league is tracking and talking about constantly. A few hundred added RPM on a ball can give it just a little more movement and make it harder to pick up from the batter’s perspective. There are other factors that need to be included here (like velocity, which we dive into on the last slide of this article) that ultimately make an RPM matter more (or less), but the point remains that this stat absolutely matters. The only question is regarding this situation is how much it matters regarding German and his Saturday performance specifically. That’s what the next slides hope to address.