Another example of Brush Interference from a very high level pitcher. This is probably the most interference I've seen but it works well for this young lady. BTW this pitch was 67 mph.
I wonder if there is a break-point where the amount of Brush Interference starts to degrade spin rate?
The ball in this vid doesn't look like it will be anywhere close to 20RPS.
But if you throw 67MPH, then maybe that doesn't matter much...