I attended an ASA fast pitch clinic last weekend and what they taught was when asking for help on a check swing was to take off your mask, walk out from behind the plate, point to your partner and ask "Did she go, or did she swing" In doing this there is no question if your are asking for help or saying she did swing. On a check swing you say “swing” and point to the batter and give a strike signal

SBJ - that's the "normal" mechanic. You need to modify it to be quicker in cases where it matters, like when the ball gets away and a swing would have made it strike 3 (thus D3K), or even when it's ball four getting away with runners on 1st or more than 1st.

My third strike mechanic:

I give the loud, strong verbal grunt (strike 3) in the set position and then a slight pause to ensure it is a caught third strike. I then give another aarrgghh!! (batter's out) when I come up and pull the bow with a strong step straight back from the catcher while my eyes stay focused on the play. My signal is a bit shorter than many in that my forward (left) fist does not extend forward but remains in front of my chest and my right fist pulls away from my right and ends under my chin.

At an NCAA evaluation last year, I was instructed that I could be 'bigger' on my called third strike, ie. extend the forward fist and pull the right back behind the ear.

My opinion, it depends on the level of ball and size of the crowd. 12U, only hammers and a mild "ha!". For higher level JO and HS with 50 people (mostly parents), my routine mechanic fits well. At an NCAA, D-1 program in a small stadium, full extension front to back; make sure grandma in left field knows (the point made by my NCAA evaluator). the point being that while you use the same mechanic, how much emphasis you use may increase as the level increases.

A little story on how the mechanics in softball have evolved:

My old man worked baseball and then softball for some 30 years (starting in the early 70s). His third strike mechanic in his early college days:

"STRIKE 3 ON THE CORNER" in a loud boisterous tone as he took one step to the right with his right hand and three fingers extended counting out each one. And of course, he watched to make sure he had three fingers extended (or he was checking someone out in the first base dugout???).