When I first started tennis I quickly learned that practicing with pressureless or flat balls and then playing a match with a fresh can of pressurized balls is two completely different things as I was launching the fresh balls into the fence and couldn't control them. So, now my daughter has gone through the ball progression of Red, Orange, and is now on green. So, I bought a bucket of Gamma green balls http://www.tennis-warehouse.com/Gamma_Quick_Kids_Green_Ball_12_Pack/descpageGAMMA-GQKB78.html When she was using orange balls I did notice that the brands of orange balls were different from eachother, so I bought a couple different brands of green balls (pressureless) and found them to all be reasonably similar. No time soon, but down the road, my daughter will probably play green ball tournaments, so I was researching them and it sounds like some of the tournaments use a can of pressurized green dot balls. So, remembering my experience between pressureless and pressurized balls I bought a can of Penn Control+ http://www.tennis-warehouse.com/Pen...s_Balls_12_Can_Case/descpageHEAD-PCPGD12.html And, holy cow, what a difference. I did a bounce comparison and the Penn Control+ bounced way higher then pressureless green balls and exactly as high as 2 week old Penn Championship Extra Duty balls http://www.tennis-warehouse.com/Pen..._Balls_24_Can_Case/descpageHEAD-PCHAMPXD.html The Penn Control + did feel slightly lighter than the Penn Championship ball though. So, my question is, what have other's experiences been with green ball tournaments and ball difference? It seems like down the road and when she is ready, I would be doing my daughter a disservice by practicing with pressureless green balls and then in a tournament they use a can of pressurized green dot balls. Basically like practicing with a flat basketball and then putting them in a game with a fully pumped up basketball. Seems like the transition should be from pressureless green balls then to old yellow balls to prepare for green dot tournaments. Is that right? One thing I haven't tested yet is if the Penn Control+ loses a lot of pressure over time. I will be able to test that in a couple weeks though. It will be interesting to see how that compares to a fresh control+ and pressureless green.