For your average NBA fan, a whistle for illegal defense might as well be a violation for too many ghosts on the court. Seemingly out of nowhere the play stops, everyone looks around confused, and you have no idea what the official saw. You just have to trust that it was real.

Jumbotrons and telecasts rarely show replays of what happened and you’re left wondering “wait, do we get free throws or what?” When you’re watching a game, you’re not glaring at the off-ball action or tracking three second counts in your head, so an illegal defense violation is both a major rule and one that you rarely see and never think about. In this week’s Whiteboard we will be discussing the history of the illegal defense rule, how it’s changed over the years, and break down the basics so you can see the ghosts too.

Oh, and it’s also completely changed the way offensive basketball is played.

NBA Illegal Defense Pre-2001

Prior to the 2001-02 NBA season, the defensive rules in the NBA were no different than your elementary schools rec league; everyone must guard their man. Zones defense, or anything that resembled one, was completely illegal. You had to be either guarding your man or the ball, and nothing in-between. You could double-team the ball and help a teammate, but it had to be clear that was was your intention. Isolation basketball, on the wing or in the post, was both efficient and effective. Here’s the original Isiah Thomas picking on John Stockton.

Look at the still shot. The offensive players really aren’t even that well spaced and Thomas still has the entire right side of the court to go to work.

Double-teams on the ball were allowed but they had to be aggressively straight-forward. If you’re going to double-team a player, it should look like this. Also, nice try…

Or this.

You weren’t allowed to double-team away from the ball and you had to be within an arms reach (approximately) of your assigned man. Even if your man was standing at half-court, you had to be positioned at least above the foul line. Coaches would actually use this as a strategy to trigger a violation. Here’s Bill Cartwright “spacing the floor.”

Gross.

These rules are what made isolation basketball the preferred method of attack in the NBA. You could throw the ball to your best player on the wing or the block and he could attack a helpless defender or easily pass out of a straightforward double-team. All of the stars of the 80s and 90s benefited from the restriction of these rules and basketball suffered aesthetically. Isolation was the smart play but it wasn’t exactly what Dr. Naismith had in mind.

NBA Illegal Defense Post-2001

In an effort to move away from iso-heavy and stagnant NBA offenses, the league changed the defense rules significantly in the 2001-2002 NBA season. All restrictions on defensive alignments were removed with the exception of the defensive three-second rule. Let’s go directly to Section VII, page 35 of the NBA rule book!

Defensive Three-Second Rule 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 arms 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/arms 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.

**Whiteboard translation** You can sort of play zone now! A team can position defenders any way they’d like, except for sitting a man in the paint for more than three seconds. If your team gets caught more than once in a game lingering in the paint, your opponent gets a free-throw. This rule has suffocated the effectiveness of isolations and post-ups and has forced teams to emphasize ball movement/player movement to get easy baskets. Let’s take the look at the wing/mid-post isolation that was the bread and butter of Michael Jordan’s game.

Poor John Starks is completely left on an island, especially since Mark Jackson has to go slide with his man across the court. If Jackson lingered too close without decisively double-teaming the ball, the whistle would blow.

In another play, you can see Scottie Pippen at the top of the frame signaling that his defender was in an illegal position. This drew a call.

Now here’s Kobe Bryant post-2001, in the same offense (the triangle) and in a similar situation.

Instead of attacking his man in space, Kobe is forced into a tough fade away. Unlike Mark Jackson, Paul Pierce is able to completely disregard his man and “zone up” the space on the floor that is vulnerable. That lingering defender that we saw get whistled against MJ is illegal no more. The game’s great individual scorers have less open space to work with and have to navigate help defenders who are there only to stop them. Tom Thibodeau was one of the first coaches to fully incorporate the zone concepts into a man-to-man defense and overload the ballside.

As soon as Iso Joe goes into his one-on-one shake, the wing defender slides into the driving lane and stops his momentum. He completely leaves his man but he doesn’t double-team. He’s just there.

Like Kobe and MJ before him, here’s Lebron isolating on the wing.

Unlike MJ, Lebron has to navigate both his man and a secondary defender standing ten feet away jumping up and down like the back of a 2-3 zone. No double-team or help-and-recover, just a human wall. A knock against Kobe is that he kept playing like it was 1993, even as the rules changed. The value of the isolation or post-up was getting fouled and getting into the paint. Jordan took plenty of tough fadeaways over double-teams, but he was also getting to the rack and drawing fouls. The isolation play is no longer the best vehicle to generate that type of efficient offense.

Remember our first clip of the original Isiah Thomas picking on John Stockton? Here’s the exact same scenario with John Wall attempting to pick on his namesake nearly 30 years later, with a much different result.

The Wizards are even more spaced out on the weakside than the Pistons were, giving Wall a maximum amount of space to operate. With the modern defensive rules, the classic clear-out play has a much different result. Instead of having to either stay close to his man or immediately double-team, Kelly Olynyk is able able to linger nearby and pounce on Wall’s turnaround jumper without him even knowing he was there.

Double-teams come at unpredictable times and help comes from all angles; it’s really amazing that any individual can score 30 points per game anymore. Our own Brad Steven has been know to play straight-up 2-3 zone in out-of-bounds situations. It essentially makes whatever play the opponent designs coming out the timeout null and void.

Illegal defense is much easier to officiate post-2001 and the only violation that you’re looking for is the three-second count on a defender in the paint who’s not actively defending the ball or his man. Thus, the “lane-hop.”

You have probably seen this funny little dance before and wondered what on-earth is going on. In the clip above, Joakim Noah quickly gets both feet out of the paint and then back in to restart his three-second clock. If you get good at the lane hop, you can linger in the paint than the rule intends.

Final Thoughts

There are certain “hot-take” topics that push me over the edge. They are:

Wing/Guard Hall of Famer X would dominate today’s NBA because there is no more hand checking Big Man Hall of Famer X would dominate today’s NBA because there are no more bigmen AAU basketball has killed post play and the mid-range game and has made the kids three-point happy

The AAU hot-take is an entire post for another day (why is AAU bad and travel hockey/soccer good?) but these generational topics shouldn’t even be a discussion. What do you think Lebron would rather have, his man hand-checking him or 2 extra defenders standing in his way? How well would Shaq fare today now that a full-generation of coaches have figured out how to suffocate the dominate post-player? The three-pointers, the pace-and-space, the value of role players, the devaluing of isolation, all of this is a ripple effect of the change in the defensive rules and in-turn the way game is played.

The game has to be watched in the appropriate context and the better you understand the impact of defensive rule changes, the better you’ll understand why the game is played like it is. I hope this was a right step in that direction!