Basketball U has the skinny on the four NBA playing rules changes implemented for 2001-02.

Illegal defence guidelines have been eliminated in their entirety.

There are three reasons why illegal defence guidelines were eliminated.

1. It was difficult for officials to recognize and administer illegal defence rules.
2. Teams used the guidelines in a way that produces isolation basketball plays for star players. Isolation plays result in less player and ball movement and few fast-break opportunities.
3. Illegal defence rules were difficult for fans to understand.

Without illegal defence guidelines, the game is expected to have better passing and ball movement, more cutting and player movement, faster play and higher scoring.

Shaquille O'Neal
Zone defences designed to collapse on big men will result in open shots to teams' perimeter shooters.
NBAE Photos
A team will push the ball before the defence sets up in order to create transition baskets, layups and dunks resulting in more open-court play.
Teams will cut and pass the ball more in an effort to find holes in the defence to take mid-range jump shots.
Motion offences and fundamental basketball plays such as the give-and-go and backdoor play will exploit overly aggressive defensive players by denying the basketball.
Centres in the high post with the ability to shoot and pass from the perimeter will be able to draw the centre defending them away from the basket or shoot over a smaller player in the zone.
Zone defences designed to collapse on a dominant big man like Shaquille O'Neal will result in open shots to a team's perimeter shooters, such as the Lakers' Kobe Bryant, as well as players cutting to the basket. O'Neal may duplicate the passing feats of former Lakers' centre Wilt Chamberlain, who led the NBA in assists in 1967-68 with an 8.6 assist-per-game average.

A new defensive three-second rule prohibits a defensive player from remaining in the lane for more than three consecutive seconds without closely guarding an offensive player.

In eliminating illegal defence, the primary concern was that teams would leave a tall shot-blocker in the middle of the lane to prohibit drives to the basket. To alleviate this concern, the defensive three-second rule was created. The penalty for this violation is a technical foul charged to the offending team. Unlike the former illegal defence rules, this is charged without warning.

The time that a team has to advance the ball past midcourt has been reduced from 10 seconds to eight.

There are two purposes for this change.

Offensively: By reducing the amount of time to cross midcourt, teams will push the ball quickly by running or passing it to the front court, rather than walking the ball up the floor. By advancing the ball quickly, the defence doesn't have the time to set up, allowing for fast-break and easy-transition opportunities.

Defensively: Reducing the time to advance the ball encourages the defence to extend its three-quarter or full-court set-up in order to create a turnover or cause an eight-second (formerly 10-second) violation.

Brief contact initiated by a defensive player is allowed if it does not impede the progress of the player with the ball.

This was designed to reduce touch fouls that were called that had little effect on the actual offensive play, but disturbed the fluidity of the game. These fouls are called at the discretion of the officials. Touch fouls that do not impede the offensive player's progress will not be called.

Knowing they will not likely be called for a touch foul or bump, players may be encouraged to aggressively defend their man both in the half court and full court.

History of Significant NBA Rules Changes

Basketball U Rules when the league launched in 1946
Games are 48 minutes long.
Players are allowed six personal fouls.
Zone defences are allowed. (Note: They are disallowed in 1947.)

The 24-second shot clock is introduced.

The three-point field goal is used on a trail basis during the regular season. The line is 22 feet in the corners extending to 23 feet, nine inches at the top of the key.

The no-charge area, formerly a two-by-six-foot box where an offensive foul is not called if contact is made with a secondary defensive player who has established a defensive position, is expanded to the area consisting of a half circle with a four-foot radius measured from the middle of the goal.