PORTLAND, ORE., JUNE 9 -- The Detroit Pistons have a rebounder who can't jump. The league's best defender can't shoot a lick. They bring an agile seven-footer off the bench in an era where almost nobody has an agile seven-footer starting.

But there they are, the league's best defensive team. That's what has gotten Detroit back to the NBA Finals for the third straight season and into Sunday's Game 3 with the Portland Trail Blazers. While most of the league humiliates opponents by jumping over them, the Pistons do it in the simplest -- and when you think about it, most effective -- way possible.

They don't let you score.

But they might have to play today without Dennis Rodman, whose sprained and bone chip-laden left ankle simply isn't allowing him to do anything approaching normal speed. Coach Chuck Daly pronounced him "very, very, very questionable" for the game, and if you haven't been to Reading Between the Lines School, that means he isn't going to play.

Mark Aguirre will start -- something he did for almost half the season before injured against the Lakers in January. After that game, Rodman was put into the starting lineup, and the Pistons soon went on a 25-1 streak.

It was the base on which Detroit the Pistons built a 59-23 regular season record. They Pistons They allowed just yielded a league-low 98.3 points per game and their opponents shot a league-low .447 opponent shooting percentage, both tops in the league. They held 22 opponents to 90 points or fewer. In the playoffs, they have allowed just 93.5 points per game, on rivals' .431 shooting by the opposition opponents.

They held Chicago to 74 points in four quarters of Game 7 of the Eastern Conference finals, one of the great displays of defense ever.

"It's like jazz musicians getting into a groove," Isiah Thomas said. "Everybody just hits the right notes and they'll get a jam session going for about 15, 20 minutes where no words need to be said. Everybody just more or less is playing their own tune, yet you're all in rhythm."

It is a disparate group. Forward Bill Laimbeer is about as different from guard Joe Dumars as is humanly possible. Yet they both defend in their own way. Whatever it is, it may have transcended defense and changed the way the game is played for years to come.

Lakers Coach "Pat Riley said to me one day that they took a page from our book," Daly said. "I've heard {Portland Coach Rick} Adelman say the same thing, and some other teams. If you understand playoff basketball, why play any other way? Because that's what playoff basketball boils down to. So we try to play that way all year." Thomas Was First

Thomas came first, the second pick overall in the 1981 draft. Laimbeer came with Kenny Carr in a 1982 trade with Cleveland for Phil Hubbard, Paul Mokeski, and a draft pick. The Bullets traded Rick Mahorn to Detroit though he's in Philadelphia now. Dumars followed in 1985, the 18th pick overall. The next year yielded both Rodman and John Salley, and the defensive cast was set.

Over the years, Daly, former Charlotte coach Dick Harter, and current Miami coach Ron Rothstein hammered defense into the Pistons. It became second nature, and it won Detroit a championship last season. When Mahorn was left unprotected in the expansion draft, it was thought that the days of great defense were over.

But Salley went back to the bench after a brief starting stint. Rodman went into the starting lineup and everything fell into place.

"We've got the defensive player of the year {Rodman} and a first team all-defense {Dumars}," Laimbeer said. "Isiah's no slouch defensively. Throw in a couple of big bodies like Buddha {James Edwards} and me and you have the makings of a pretty good defensive team."

Both Thomas and Dumars can defend out front. Rodman will take anybody in the league one-on-one. But what separates the Pistons from other teams is their ability to help out. Every player in the league gets beaten. But few teams have the ability to make up for it and still take away the shot.

"A lot of times you only have a couple of good individual defenders on the ball or you may get a good team concept," Adelman said. "But they've got both going. Not only good individual defenders on the three main spots, the two guards and the small forward, which you need, but they're good as a team."

No one likes to acknowledge that Laimbeer is a pretty fundamentally sound defender. And in the last eight seasons, how many people have more rebounds than Laimbeer's 7,587?

One. Atlanta's Moses Malone.

Aguirre talks about playing defense now. Ask around. That's unusual.

The key is Rodman. The Pistons went back and forth in the 1986 draft between Rodman and Kevin Duckworth, who eventually was drafted by San Antonio. Duckworth's weight scared them and they took Rodman. He doesn't like starting, but he gives them the dimension they lacked.

"He has learned that it is something that he does great," General Manager Jack McCloskey said. "He's the best individual defender I've ever seen. He's playing hurt now and he did a great job on {Jerome} Kersey the other day. He's just so, so good and I think he recognizes that and takes a great deal of pride in that."

By going back to the bench, Salley now does not have to worry as much about carrying his load offensively. He can concentrate almost exclusively on helping out on defense and blocking shots.

He had 14 points and five blocks in the seventh-game victory over Chicago, and is already Detroit's all-time playoff leader in blocks with 104.

"How many teams in the NBA," assistant coach Brendan Malone asked, "have a seven-footer who blocks, but more importantly, changes shots, coming off the bench? How many teams have a weapon like John Salley?"