If you're battling a Sim, it's not very difficult to turn the player green if you hit him early, within the first 2 or 3 cycles. In D2, it'll usually take your ac scout trip, then anywhere from 1 to 4 campus visits. If you're battling another human, you never know how much it'll take. You probably don't want to battle too many humans unless you have a substantial distance or money advantage.