Not Important For Getting Better In A Drill Group:
1) Exclusively playing with better players - When a parent says their child wants to be in a group that is stronger than their level, this tells me that the child wants to artificially feel like he/she is stronger than he really is or maybe the parents want to tell their friends the strong group their child got into. When your child is practicing against stronger players, they are spending all of their energy catching up to the pace of the group,not on getting better. Additionally, the child is learning how to lose.
2) Playing Exclusively With your gender - If the group is for social reasons, gender is important. If it's to get better, gender doesn't matter. Women pros have male hitting partners. Females often hit a cleaner ball than boys and could give boys a good rhythm.
3) Playing Exclusively with older kids - If the older boys are overpowering your child one shot and missing the next shot, this isn't a good practice. If you are moving up to high school from middle school or transitioning up an age group, there is some short-term usefullness.
4) Playing in a drill group that has a star player who your child will never play with - it's funny how a top eastern player draws other kids into a program when most of the kids will never step on a court with that top player but instead will gawk from a couple of courts away.
Important For Getting Better In A Drill Group:
1) Playing with players who have the same goals as your child - This is extremely important. You want kids who are looking to work hard if your child wants to work hard and a group of social kids if you child wants to besocial
2) Playing with pros who truly want to be there and who truly want to see your child get better - You are not looking for a drill group pro to entirely change what your personal coach is working on, but you do want an enthusiastic coach who has the same goals that you do for your child
3) Playing in groups where you could be the best at times, the middle at times and the weakest at times - This is where players improve the most. When you are the best on your court, you can practice things that aren't match ready because you can dictate the exchanges in the group. When you are in the middle of the pack, you can practice things like competing hard and trying to win. When you are playing with stronger players, you can see where your game needs improvement. A 1/3, 1/3, 1/3 formula works best in my opinion.