this is a 3v2 drill where the ball starts with a player or coach who inbounds it to the first player who throws back to the second player and on to the third player. As the ball is moving the players are getting into the 3v2 triangle and they push the ball, reacting to the defense and trying to score. Offense lines are on both or one side of the box. Defense lines are at X. When the current drill ends the next drill begins, this should be fast and the current players need to clear the field as the new players are coming on, or atleast thats the gist.