“This is an example of an offensive foul for illegally wiping away an opponent’s arm. The post defender, Nemanja Bjelica, legally places his right hand on the back of Bobby Portis, the offensive player with the ball and his back to the basket. The offensive player then uses his left arm to knock away the defender’s arm. This is an offensive foul, as a player cannot initiate contact to wipe away an opponent’s legal arm. Note that inside the lower defensive box – the area from bottom tip of the free throw circle to the 3′ posted up marks – a post defender may legally place one hand, with a bent elbow, and/or one forearm onto the back of an offensive player with the ball and his back to the basket.”