do you think is gained from the push? And how much push is required to make a noticeable difference in the dunker's height/end result? If the dunker is losing altitude, probably much more than the dunker is capable of exerting midflight. And if the dunker is still climbing, the extra height gained from the push off still seems likely to be insignificant as well considering the mass and forces involved. The person being jumped likely absorbs much of the push in any event and probably the biggest benefit to the dunker is the (perceived?) additional sense of balance he might get during the jump.