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

Domingo German cheating theory: Spin rate drop could be fatigue

Yankees fans clung to this argument tightly on Saturday. Spin rate can naturally drop throughout the day as pitchers get fatigued and their pitch count climbs. The idea behind this argument is that the drop in spin rate was coincidental, not incidental to the timing of the “wash your hands” conversation German had with umpires.

To assess the validity of that argument, we should compare his Saturday start and the drop in average spin rate to other similar starts.

Unfortunately, this is hard to do so early in the season. German pitched 6.1 innings on Saturday, the lengthiest start he’s put out this season. Prior, he pitched 4.2 in his season opener and then 3.0 in his second game. Since the incident happened after three innings, we can really only compare it to the first game of the year.

Here is, in terms of percent decline, how German’s spin rate changed in his first start (April 4) compared to Saturday’s start.

The pitches that declined at a far worse rate than they did in his debut game of the season were the curveball and the changeup.

Conclusion: Sinker spin rate change plausibly due to fatigue

The sinker was the worst change in spin rate for Domingo German on Saturday at 4.86% decline. He lost 124 revolutions per minute on the pitch after the incident. Clearly, though, that’s at least plausibly due to fatigue since he lost a similar amount of bite on that pitch in his first outing.

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