I'm looking for a ball machine to get some extra hours on court. I am a 16 year old high level junior player, say 5.5. what exactly does oscillation mean? the machine must be portable with a re chargeable battery. It must hold a decent amount of balls. It must have different spins and trajectory and decently high speed to challenge me. I really want one that I can do different patterns with say backhand crosscourt, backhand crosscourt, forehand dtl. I would like random with.different depth, spin etc, but it is not necessary. I don't need remote, fast charger or any other things that make it easier, I care more about the actual quality and functionality of the machine. I don't have a specific price as I feel I will save a lot on lessons, but I basically want is cheap as possible, I'M PAYING FOR IT! I'm somewhat intrigued by the silent partner machines but am not exactly sure what all the features mean, and if any of them have what I'm looking for.