played, knows that the pitcher pump faking is completely normal. In fact, it's not normal when you have a pitcher that doesn't.
The pump fake can throw the hitter's balance off, and get in their head a little bit. I've become pretty good at pump fake/quick pitch if I see them flinch.

Last night, I'm pitching, and i throw 2 pump fakes at a guy (he bit on both, big flinches), then he proceeded to hit a weak pop fly to our short stop.

After he gets out, he runs to the ump and asks in a whiny tone, "is that even legal?!", to which the ump looked confused as to what he was asking about. On his way back to his dug out, he starts yelling at me for being bush league, and that I won't pump fake anymore when he hits up the middle next time.

I keep pitching like I do, which at the next half-inning break, he talks to the ump about it more. I overhear the ump say you can pump fake 5 times.

His next at bat I made sure he got all 5. Bro was bitter as crap, wouldn't fist bump/high five in the line after the game haha

https://www.youtube.com/shorts/YHZg3iJz7zY