The basic idea of the drill is to get a certain number of consecutive hits of the required type at each level to earn a move up to the next level. You can adjust the drill to the skill of the players by changing the required number of consecutive hits. The number should be a multiple of four, because the hitting patterns cycle by two or four. Four is usually about right for beginners, eight for intermediates, twelve for advanced intermediates, and sixteen for advanced players.
If you're running this drill with lots of beginners, you should circulate as much as possible, hitting with each member of a pair who have gotten stuck on a certain level. If you pass that level hitting with each of them, they get to move on to the next level as if they has passed it hitting with each other.
The diagrams assume two right-handed players. If one or both players are lefties, the written instructions overrule the diagrams.
Level 1 is a gentle, all-forehand rally from the service line.
