25 chops per second would be EXTRAORDINARY. Possible? Probably but only with super elite training. Most competent home chefs can probably do 5 Hz and probably struggle to get to 10 Hz.
Looks like around 12Hz, counting the forward rock and back rock as distinct chops. I'm not sure a rocking motion is what people mean here, though. This only works for mincing something you've already cut up, not slicing an onion.
Maybe the solution is an ultrasonic slap chop? (https://www.amazon.com/Slap-Chop-Stainless-Vegetable-Accesso...) Many slices at once, preserve whatever the ingredient is without crushing it, doesn't stick to the blade. It may sound ridiculous, but if it makes kitchen prep easier and faster, I might cook more.
The sixteenth notes in "Crazy Train"[1] are nominally 552 per minute, or 9.2 Hz. Moving a knife at 10 Hz is probably very difficult. I would expect 2-3 Hz is a normal pace for a skilled knife user and 4-5 Hz is showing off.
