So, when one partner is driving does the person driving keep moving forward slowly and the other person goes back? Like a drive battle. The way I learned is when that happens up split until a shot is different. And also I was told once that the person driving will slowly step forward with each step.
From what I know, you should stand in your positions until there is a change of drive shot. If you can drive it to go more down, you go forward while your partner moves more behind you. If you drive it to go more high, than you move backward, while your partner sees the situation, if it isn't too high , he can go forward, but if it's a loose ball, he should prepare for a kill by going back. (the situation where you do a loose ball begging to be killed by your opponents may become the norm, so both of you should go back and defend in the middle court to prepare for a kill, but also be prepared for a drop or netshot) How far you go forward or how far you go back depends on how low or how high the drive you do.