He must judge the speed of the receiver and when threatened he must open his hips and execute a 180 degree tum .
Each defenslve back must know his own limitations as to when his cushion is threatened to be broken .
defenslve must judge the speed of the receiver and when threatened defenslve must open defenslve 's hips and execute a 180 degree tum .
Each defenslve back must know his own limitations as to when his cushion is threatened to be broken .