You pitchers who feel you could throw faster/harder;
You all probably play long-toss, but try this method--it could help you.
Go to the outfield and shag fly balls & ground balls. Take a crow hop and throw the ball as hard as you can on a straight line back to home plate. After about 20 throws,
move back onto the pitching rubber and pitch. Now, the key here is to throw with the same motion and speed you threw from the outfield(less the crow hop). And remember, you throw THROUGH your target & catcher,
like you want to put the ball through to the backstop. You should pick up
speed. Note: you will probably loose control and throw very low when you come back to the mound, this is natural, and your control will return.
Try it for a month & see what happens, it cant hurt ya. Bill
P.S. I'm not saying the advice about mechanics is bad either--its good.
But try the drill too.