In the last 10 years the NBA had its small forward phase, where you couldn't win unless you had a great scorer at that position. It had its Twin Towers phase, where you had to have two space eaters in the game at the same time. As the 1990-91 season starts, the new thing is the Detroit Shuffle.

Or, the three-guard rotation.

The longest legacy the two-time defending champions may leave on the game is that their success is shifting attention away from the lane and into the backcourt. Bigger does not necessarily mean better. And a lot of teams invested this summer in trying to develop a trio that does for them what Isiah Thomas, Joe Dumars and Vinnie Johnson bring to the Pistons.

The Dallas Mavericks brought in two-time all-star Fat Lever from Denver to go with Derek Harper and Rolando Blackman. Portland traded for Danny Ainge to rotate with Terry Porter and Clyde Drexler. The Lakers continued their three-guard setup by acquiring Terry Teagle from Golden State to team with Magic Johnson and Byron Scott.

"If you look at Detroit and the success they had," Dallas Coach Richie Adubato said, "that was a three-guard rotation. They didn't start Vinnie and Isiah and Joe Dumars together. . . . We'll rotate the three guards, giving them equal time, but sometimes during the course of the game you could see Ro {Blackman} at small forward."

The Mavericks are only one of a half-dozen teams in the West that could challenge. Portland is back, Phoenix is smarting after two Western Conference finals losses. San Antonio's Spurs are a year older, Utah added Jeff Malone to the Karl Malone-John Stockton duo and the Lakers are the Lakers.

Well, not exactly. Mike Dunleavy, the former Milwaukee assistant, takes over for Pat Riley, who won four titles in nine seasons as coach. And the Lakers sport Sam Perkins, an unrestricted free agent signee, who may start in the pivot after the disappointing camp of Vlade Divac.

"I had heard coming in how good they were as far as character was concerned," Dunleavy said. "And I found that to be really true. We've got really good people and it helps because they tend to keep each other up. They're willing to work hard when it needs to be done. They're just great guys."

But the biggest story in the West is the Denver Nuggets under new coach Paul Westhead. He is trying to install his freewheeling, high-scoring system from Loyola Marymount into a skeptical league. Many believe that not only will most scoring records fall this season, but that both a 200-point (team) and 100-point (individual) game is possible.

Denver's, uh, offense, is predicated on the principle that using eight seconds of the shot clock is too long. And on defense, the Nuggets press full court. If they don't get a steal in the backcourt, they usually give up an easy basket. The idea is that no one can play at that pace for that long without a slew of turnovers. While testing it out, Denver gave up 184 and 194 points in two preseason games.

Westhead isn't worried.

"I know it is doable," he said. "I know what the pro athlete can do. I know he is the supreme athlete and he's certainly capable of performing any and all tasks. That gives me a sense of confidence that I can bring this system and bring it into play."

When we last left the Pistons, Chuck Daly was on his way to NBC and the analyst's job that eventually went to Mike Fratello. But Daly got a two-year contract extension last summer and everything is in place for Detroit to try to become the first team since Boston's string of eight straight titles from 1959 through 1966 to win three consecutive championships.

"I thought at one time I would probably wind up with NBC," Daly said. "When I started to really think the process out I had decided I really hadn't made plans to give up coaching. And I didn't think I was ready to give up coaching. It's the one thing I know something about. . . . The lure of winning a third title, I just couldn't walk away. And I know how difficult that's going to be."

The Pistons not only have to stay healthy -- Thomas (ruptured tear duct) and Bill Laimbeer (fractured cheek) both were hurt in preseason -- but they have to again hold off the Chicago Bulls, who feel their losses to Detroit in the last two Eastern Conference finals have toughened them much the way the Pistons were after losses in the mid-'80s.

"You have to earn your stripes in this game," Bulls Coach Phil Jackson said. "When I was with the Knicks in the late '60s and early '70s we had to get beat by Boston before we could try to become champs on our own. It seems to be something every championship team has to go through. They have to have the experience, the heat and the duress that only playoff basketball can give you. And we've been through it now a couple of years in a row."

Cleveland is healthy for a change and brings in Danny Ferry from Italy, finally completing the Ron Harper trade. Atlanta has a new coach (Bob Weiss) and a new mandate to run, something the Hawks did as well as anyone in their salad days.

In the Atlantic, the Celtics are starting over with new coach Chris Ford after their humiliating first-round loss to the Knicks last year. Philadelphia bolstered its lineup by adding designated swatter Manute Bol to its division-winning team.

"It's been a pleasant surprise playing with him," Charles Barkley said. "I only want good people on this team. He comes back at you. He has a great personality. He's one of our team pranksters."

And in New York, Mark Jackson came to camp in shape with a new resolve, and appears as if he'll get his starting point guard spot back for the Knicks. They don't have a three-guard rotation. They have Patrick Ewing. A good start.

MIKE DUNLEAVY Los Angeles Lakers No previous head coaching experience; assistant, Milwaukee Bucks, 1987-90.

CHRIS FORD Boston Celtics No previous head coaching experience; assistant, Celtics, 1983-90.

K.C. JONES Seattle SuperSonics Former coach, Washington Bullets, Boston Celtics. Regular season record (nine years): 463-193. Playoffs: 79-54. Won NBA championship, 1984, 1986.

PAUL WESTHEAD Denver Nuggets Former coach, Los Angeles Lakers, Chicago Bulls. Regular season record (four years): 139-104. Playoffs: 13-6. Won NBA championship, 1981.

MIKE SCHULER Los Angeles Clippers Former coach, Portland Trail Blazers. Regular season record (three years): 127-84. Playoffs: 2-6. Coach of the year, 1987.

BOB WEISS Atlanta Hawks Former coach, San Antonio Spurs. Regular season record (two years): 59-105. Playoffs: 0-3.

DERRICK COLEMAN New Jersey Nets F, 6-10, 230 pounds, Syracuse First round, first pick overall

GARY PAYTON Seattle SuperSonics G, 6-4, 180 pounds, Oregon St. First round, second pick overall

DENNIS SCOTT Orlando Magic G, 6-8, 230 pounds, Ga. Tech First round, fourth pick overall

KENDALL GILL Charlotte Hornets G, 6-5, 195 pounds, Illinois. First round, fifth pick overall.

DANNY FERRY Cleveland Cavaliers F, 6-10, 230 pounds, Duke Rights acquired with G Reggie Williams last season for G Ron Harper, 1990 and 1992 first-round picks and 1991 second-round pick.

TRAVIS MAYS Sacramento Kings G, 6-2, 190 pounds, Texas First round, 14th pick overall

DEE BROWN Boston Celtics G, 6-1, 160 pounds, Jacksonville First round, 19th pick overall

GERALD GLASS Minnesota Timberwolves G, 6-5, 240 pounds, Mississippi First round, 20th pick overall