Tex,
Glad to hear that your girls are working hard to get better behind the plate.
First off, I do have to comment on Jim's suggestion to start turning the shoulder and knee early in an effort to speed up the release. The suggestion was certainly made with good intentions, but not only will this actually end up slowing down the throw because of the risk of the girls actually moving too far their left with their right foot as a result of the turn of the hips (can't turn shoulder and knee without the hips turning as well), but it will most definitely force each of these girls to develop a very flawed throwing motion, with their front side swinging open early during the throw. This will completely eliminate the lower half of their body in the throw, resulting in a push of the ball rather than creating whip of the arm with the drive and rotation of the hips and lower body. It is the lower half that should power a throw, not the turn of the shoulders.
We have to think of the throw as a continuous movement, but one with check points. Or rather, a row of dominos...when evenly spaced and pushed down in order, all of the dominos will fall, completing the motion. For arguments sake, let's say that the proper throwing motion has 30 steps or "dominos" (completely arbitrary number). Domino #8 is the rotation of the hips and shoulder towards our target. We take that domino out of the row and put it in front of domino #1. Now push them down. What happens when we get to domino #9? Nothing. We have to add a step or "domino" and now the throwing motion that should have 30 steps when executed efficiently, now has 31. Most of the time, the step/domino that is added naturally is the same one that was taken out. The turn of the shoulder and hips. We will end up over-rotating, pulling open far too early in the throw with our front shoulder, most likely causing the throwing arm to drift away from the body (possibly letting the elbow drop) and now we end up sailing the ball into high right into the outfield. All because we tried to turn early. I don't want to turn early, I want to turn on time. There is a proper sequence to a throw. Cheating at any point in the process will increase the release time and will disrupt the overall mechanical efficiency/accuracy in the throw.
One thing to remember when working with 10U's is that the momentum of the pitch may carry a force much greater than what their arms are physically able to handle. That "recoil" of the arm, hand and glove will most certainly contribute to a slower exchange, and thus a slower throw.
Also, one of the things that I have learned through all the years I have been doing this with my father is that progression of the training environment is pivotal in the development of skills. If they are always starting with the ball in their glove, then the second they experience the tactile feel of a ball hitting their glove, a different part of their brain will take over the reigns in the throw, completely ignoring the muscle memory they have developed during drills when the ball starts in their glove.
All this means is that these girls need to practice throwing off of more live pitches during their training sessions. The more they are able to adjust in a training environment to a moving ball, the easier it will be for muscle memory to take over during a game. It's sort of like the stances we teach. At first, I am sure some of the girls felt a bit of discomfort using muscles in their legs they had never been asked to before. But each time they got into those stances, it most likely got easier. Same thing with the throw. The more times they catch live pitches and go through the throwing mechanics, the easier it will get to repeat on a consistent basis. The impact of the ball should not be underestimated. And the importance of simply getting the ball out of their glove, out of their hand and into the air should be something that is hammered home each and every rep during the drill.
Also, at the end of the day, we do have to realize that these girls are still 9 and 10 years old. As long as they are using solid mechanics during their game-throws, actually throwing runners out literally means nothing to me until they are 14. At the 10U level, the most important skill these girls can improve on is blocking, hands down. It's great to have a catcher back there who can intimidate the other team with their arm, it is even better to take runs off the opposing scoreboard by blocking everything in the dirt and forcing teams to out hit you in order to win. They are in the process of growing, getting stronger and still learning how to deal with the big round ball flying at them, each year fast than the last. The throws will come in time.
Please don't hesitate to get in touch with me if you have any other questions. Jay@catchingcamp.com. Like Gordo said, it might take me a day or so to respond, with our road trip season starting here in a week, but I try to make sure I get back to everyone who e-mails me within a couple days, if not much sooner. I too consider every catcher, coach or parent who subscribes to our way of teaching catching a personal student of the camp.
Take care.
