after 3 years at 10u... I've had the pleasure to work with nearly 10 or more pitchers, 5 or 6 would be starters on nearly anytime I've seen or heard of (not because of me). Only 3 of them attempted to throw the drop ball. Now... all of these pitchers have what I would call good control at 10u and if not mastered the change-up throw it with 80% or better effectiveness. I'M NOT A PITCHING COACH NOR WILL NEVER CLAIM TO BE... not my core strength... Now, each girl has progressively thrown their drop ball somewhere around 5mph or lower than their fast ball with control issues as expected early on. With the incredible work ethic that some of these girls have they have gained control and speed with time and have become very effective. One throws very consistantly at 48-50 mph (fastball) and at this point she throws her drop right there too. In fact, I'd swear there's no difference but I don't want to say that's a fact because it may be just "where she's at" with her development as a pitcher. Control hasn't been an issue with her either. The 2nd girl has a difference in speed between the 2 pitches but has incredible control and quite honestly I like the difference because it may suit us better as a team and as whole.
I haven't been exposed to as many as some on the forum but I will say work ethic has been a major reason for the 2 I'm talking about here. We rarely get the gun out and in fact the speeds mentioned earlier were told to my by the opposing team. Heck, my gun may not even have batteries in it.
IMO, if a 10u is throwing strikes....or better yet, able to get ahead in the count or manage her "batter" with the help of the coach/catcher calling the game, the ability to mix up the pitches the batter sees is crucial. Now, this is the minority and not all 10u's throw in the upper 40's or even break 50. If I had to guess...in 2009, less than 5 10u's (and I'm talking May-July) in Ohio threw in the 50's (with control and execution) and for some reason loooots of teams still won games. Nevertheless, the 10u's that are throwing a nasty change and with control and have a fastball of 42-47mph will get to Sunday many times and will land themselves hardware quite often without a drop ball. I would do as so many others have said and get the control managed and then the rest will work itself out. Their pitching coach (for my team it's Buster and Misty) will get them where they should be speed wise and with game management the girls can be very successful without speed being the focus.