As next group 4-5-6 do the same thing going away, 1-2-3 are coming back. 3 is the ballhandler, again on the right side of the centre circle. 2 stays on his side, 1 replaces 3, 2 and 1 run outside the court, 3 passes to 1 for a shot (the same player can't shoot twice in a row).
Start with a target of 20 3's in two minutes. If you don't make it, do it again. Once you reach or exceed it, next time add 2 to your makes for the new target.