after hands come together, for 1-10seconds, the pitcher must immediately deliver the pitch.
maybe that was why you thought 10 seconds?
I've been thinking about this lately...
My DD tends to like to work quickly,
and often times shes taken the plate only to wait for the batter to set.
Sometimes, her hands are already together, while waiting, and thus hands have been together for more than 10 seconds.
So, I told her to not bring hands together until Umpire signals for the pitch.
My initial thought was to have her hang behind the plate, until batter is set in the box,
and then step on the plate and deliver the pitch.
But as I watched a bunch of NCAA games this week and last,
i see this is a bit of a cat-and-mouse game.
Take FLA ST. pitcher Meghan King.
She likes to work FAST. Always on the plate waiting for the batter.
And batters tend to take their sweet 'ol time getting ready - probably to try and throw off her preference for a quick rhythm.
Other pitchers wont take the plate, until the batter is entirely in the box.
So, I suppose either approach is fine.
Whichever your pitcher is most comfortable with.
But I tend to lean toward staying off the plate until Batter is set.
A pitcher can't IP until they take the plate, and can't reasonably be subject to the 20sec rule,
if the umpire is allowing batters to exit the box between pitches, and take their sweet' ol time re-setting...
Stay off the pitchers plate! Have yet to have a pitcher that I needed to speed up and I have yet to have one that I did need to slow down. I strongly encourage having her wait until the batter assumes the position prior to getting the signal, then proceed to the pitchers plate. I say this for a couple of reasons. First it helps slow her down. Second how do you, the catcher, or anyone call a pitch if you have no idea where the batter is in the box? However, the hardest part is to get them to do what is needed between when they get the signal and break their hands. This is where pitchers end up rushing, failing to commit, visualize, etc. This is one of many reasons why I really like using arm bands for pitch calling. Pitcher gets signal behind plate and catcher gets signal while standing allowing the catcher to control the pitchers tempo if needed. Great when you have an experienced catcher and noob pitcher.