In the isolation play above, player 1 goes it alone against A. Player C may double-team 1; otherwise he must stay in the weak-side upper zone. If player B visits the strong side of the lane for more than 2.9 seconds, blow the whistle. He's illegal. In the setup below, defenders A and B are free to double-team player 3 as long as the ball stays on their side of the court. Outside the NBA, this is known as a zone. If C sags back to block 5's path to the hoop, whistle him: Weaksiders 4 and 5 can't be doubled. Weakside defenders D and E are only allowed to play their men or attack the ball.