• Print
Basketball 101
Rulebook 101: Defensive Three-Second Rule

In this edition of Basketball 101, Rockets.com delves into the enigma that is the NBA rule book. Periodically, Rockets.com will pick one of the more misunderstood rules in the NBA, offer the league definition and a version more suitable for those of us who never went to law school. Who knows why the league feels they need to word their rulebook so ambiguously? Hopefully, this will help the next time you are watching our Rockets. Today, we examine a defensive three-second violation.

Rule 10, Section VII Defensive Three-Second

By the Book:
a. The count starts when the offensive team is in control of the ball in the frontcourt.
b. Any defensive player, who is positioned in the 16-foot lane or the area extending 4 feet past the lane endline, must be actively guarding an opponent within three seconds. Actively guarding means being within arm’s length of an offensive player and in a guarding position.
c. Any defensive player may play any offensive player. The defenders may double-team any player.
d. The defensive three-second count is suspended when: (1) a player is in the act of shooting, (2) there is a loss of team control, (3) the defender is actively guarding an opponent, (4) the defender completely clears the 16-foot lane or (5) it is imminent the defender will become legal.
e. If the defender is guarding the player with the ball, he may be located in the 16-foot lane. This defender is not required to be in an actively guarding/arm’s distance position. If another defender actively guards the player with the ball, the original defender must actively guard an opponent or exit the 16-foot lane. Once the offensive player passes the ball, the defender must actively guard an opponent or exit the 16-foot lane.

PENALTY: A technical foul shall be assessed. The offensive team retains possession on the sideline at the free throw line extended nearest the point of interruption. The shot clock shall remain the same as when play was interrupted or reset to 14 seconds, whichever is greater.

If a violation is whistled during a successful field goal attempt, the violation shall be ignored and play shall resume as after any successful basket.

Now let’s break down each part of this rule. It really is not that complicated.

a. When the ball crosses midcourt after the offensive team has inbounded the ball, the referee can start the count of any defender who may be in the lane at this time and is not actively guarding anyone.
b. Basically, you need to be guarding a player, not the basket. With zone defense becoming more and more prevalent in the NBA, without defensive three seconds, a team with an outstanding shot blocker (e.g., Dikembe Mutombo) could camp him under the net to deter anyone driving the lane, making the game pretty boring. A player must at least appear to be guarding someone, not just extending his arm to demonstrate that he is within arm’s reach.
c. A player may guard any opponent. It doesn’t need to be the same player that is guarding him at the other end of the floor, though this makes transition defense much more manageable. Rockets fans are quite familiar with double teams as Tracy McGrady and Yao Ming garner more than their fair share.
d. When the offensive team loses possession, whether it is a loose ball or a shot at the basket, the count is suspended. If a player leaves the violation area, most likely the lane, the count is suspended. If a player is in the process of moving toward an offensive player, the count is suspended.
e. If the defender is guarding the ball, he can be in the lane as much as he wants as long as his player and/or the ball stay there. If someone comes to double-team the ball, the original player must actively guard the player, or find another player to actively defend in the lane, or leave the lane.

PENALTY: One shot from the free throw line by any player the offensive team selects to shoot it. The offensive team retains possession and inbounds the ball from the side closest to the point where the foul occurred, but not below the free-throw line. The shot clock will stay where it was before the free throw or reset to 14 seconds, whichever is more time.

If a shot goes up and is good and the whistle blows for a violation, the violation is ignored, the basket counts, and the game continues.