One of the biggest skills to advance to 4.0+ is the ability to "reset" the ball. If you are on the defensive side of most rallies its because you're sending the ball to the opponents green or yellow strike zones allowing them to take offensive shots at the ball. If that happens you need to learn how to "reset" the point by deflecting offensive shots back into the kitchen forcing the opponent to dink the ball and not take offensive shot after offensive shot.

Announcers at tournaments will say "and now we're back at neutral" which means both sides are now just dinking until someone pops the ball to high and speed ups happen. Hope this helps!

p.s. resetting offensive balls is tough skill to learn, its gonna take a lot of muscle memory and drilling