By 1980, almost everyone in the league had begun to s-t-r-e-t-c-h the cold, stark fact of man-to-man exclusivity. Teams began to "double down" on the big front lines underneath. The defender was counseled to overplay the best offensive players, slide off his "man" if he wasn't a point scorer and provide help. Clever centers like Kareem Abdul-Jabbar specialized in the variation defense called the "NBA zone," clogging the middle just enough to discourage entry, yet avoid technicals.
Complaints about zones became frequent, and in 1981 a committee (Nelson, Motta and Fitzsimmons, with input from Garretson and Killilea) was formed to establish guidelines, which it did during an eight-hour session in Chicago.
Fans need not know every nuance of the guidelines (as we have already seen, no one does) but should be aware of their purpose, which is to maintain a pick-and-roll game and to discourage an outside jump-shooting league.
Like Gaul, the court is now divided into three parts (see diagrams). Unless he is double-teaming the man with the ball, a defender must stay within one defensive area of his man. So if an offensive player—whether he has the ball or not—is in the upper defensive area, i.e., above the foul line, his defender cannot be any nearer the basket than the middle defensive area, i.e., the bottom of the foul circle. This prevents big men from hanging back and clogging the lane when their men are stationed up high. Also, a defender is not allowed in the inside foul lane for longer than 2.9 seconds unless his man is "posted up," stationed adjacent to the key—many fans aren't aware that there is a three-second violation on defense. And double-teaming a man on the weak side, i.e., away from the ball, is prohibited.
Simple enough (or maybe it isn't), but all sorts of conundrums can develop for two reasons: First, guidelines do not apply when the ball has not passed mid-court (i.e., when it's in the offensive team's backcourt), and second, there are no restrictions against "trapping" or double-teaming the player with the ball, except that the trap must be "aggressive." But when is a trap not a zone? Obviously, when two or more defenders set off in pursuit of the ball, the remaining ones have to pick up loose men, creating a "rotation" that is difficult to monitor.
The Knicks under Hubie Brown constantly press full-court, often with a 1-3-1 zone. "After a made free throw or field goal," says guard Darrell Walker, "we're coming after you." They start it near the end line just after the opposition has taken the ball out of bounds—perfectly legal—and they attempt to force the ball to one outside alley or the other and double-team it in a corner of the court, which is also perfectly legal. It is a zone, pure and simple, but the kind of zone that the rules allow. It was so slick that last season it brought the Knicks the league lead in illegal defenses with 90. Watch complaints about the legality of Hubie's press soar this year when Ewing starts "rotating."
Milwaukee, arguably the best defensive team in the league last season, seems to draw the most fire about its tactics. In Nelson's system defenders switch every time offensive players cross—or anytime a potential pick is set. At all times the Bucks' strategy is to keep their own big men under the basket. Golden State coach John Bach says the Cavs and Celtics are two other teams expert in using partial zone on a switch.
Systems aside, there are teams that rely upon "team defenders." When someone calls an opponent a team defender, he means: "That s.o.b. plays zone 90 percent of the time." The leading team defender, by acclamation, is Larry Bird, who on a remarkable number of occasions has been seen drawing offensive fouls and just plain getting in the way of players who aren't his to guard. Ironically, the cover of this year's official NBA Guide is a perfect illustration—Michael Jordan, openmouthed, is driving to the basket and there is Bird underneath on defense, even though Bird would almost never have the responsibility for checking a speedster like Jordan.
Bird plays smart, and smart players test the limits of rules. Abdul-Jabbar has done it for years. Bird has everything about the guidelines figured out, including the fact that because the game moves so swiftly and it is impossible for anyone on the floor to watch the entire court, officials are disinclined to call illegal defenses more than once or twice a game—note that the 1,193 illegal defense calls in 1984-85 occurred in 943 games and produced only 157 free throws.
Even then, it's not a bad foul to take: The first violation results only in a resetting of the 24-second clock (unless it occurs in the final 24 seconds of a period), and all others award one technical foul shot to the offensive team. Says Bird, "If you can get two or three steals before they call it, you're ahead of the game."