In 2001, the NBA's owners approved of four rule changes in the hopes of improving the "flow and pace" of the game.
The most significant of those rules was defensive three seconds.
Former Suns owner Jerry Colangelo believed that it could end up being "one of the most significant changes" since the league implemented a shot clock. While some didn't like it at the time — Shaquille O'Neal said it "stinks" — there's no denying that it has opened up the game.
How exactly does defensive three seconds work? Let's take a closer look.
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What is an illegal defense in the NBA?
Defensive three seconds and illegal defense is used synonymously.
The NBA implemented the rule to prevent defenders from planting themselves underneath the basket. When a defender is in the paint, they must be "actively guarding an opponent," meaning they are within arm's length of an offensive player and in a guarding position, within three seconds.
Also known as the lane or key, the paint is the rectangular area between the free throw line and baseline.
If the defender gets whistled for defensive three seconds, a technical foul is assessed, resulting in a free throw and possession of the ball for the opposing team.
According to the rule book, the count starts when the opposing team is in control of the ball in the frontcourt. It's stopped if one of the following happens:
- A player is in the act of shooting.
- There is a loss of team control.
- The defender is actively guarding an opponent.
- The defender completely clears the 16-foot lane.
- It is imminent the defender will become legal.
How defenders avoid defensive three seconds
There are a few well-known ways that defenders skirt the defensive three-second rules.
The first is that defenders can hang out in the paint as long as they like if they are guarding the player in possession of the ball. Once the player gives up the ball, however, the defender either has to "actively guard" them or clear the lane.
You'll sometimes see teams have their best shot blocker defend the weakest shooter on the opposing team even if they play a different position so that they can stay closer to the basket.
This is an extreme example of LeBron James doing it to Ben Simmons:
LeBron’s defense on Ben Simmons here is so disrespectful💀💀 pic.twitter.com/8cx6AW6OLf
— Hoop Central (@TheHoopCentral) May 11, 2020
Another tactic that has grown in popularity is called cleansing.
As The Athletic's Eric Nehm detailed, it's something Defensive Player of the Year finalist Brook Lopez does particularly well. When he's in the paint and someone he's not defending cuts around him, he'll touch them to "cleanse" himself of the three seconds count because he's "actively guarding an opponent."
“When someone comes through, it’s just a touch,” Lopez explained to Nehm. “Or if there is a back cut, just reach out and get that little touch and honestly they (the officials) give it to you sometimes as they just pass by (smiles). We’re just passing ships in the night and you don’t get him."
Lopez has also mastered the art of 2.9-ing or "two-nineing," which is when the defender will take a step outside of the key for a split-second to reset the defensive three seconds count.
You can see Raptors star Pascal Siakam try to do it here, but his right foot didn't quite clear the lane in time:
Some offensive players will use that to their advantage, knowing that a defender can't stay in the paint for more than 2.9 seconds.
Notice how Nikola Jokic points at Jusuf Nurkic to draw attention to him hanging in the paint and then attacks Damian Lillard when Nurkic steps outside of the paint.
LeBron James has become particularly good at punishing defenders for "two-nineing."
