So you're on a fast break, dribbling the ball across midcourt, flying, truly flying, flying as fast as those pudgy little legs will take you. The last time you moved so fast, it was on a fast break to dinner and you're carrying lots of dinners under that Bullet jersey, maybe 20 pounds too many to be out there leading a fast break with your team seven points behind with 3 1/2 minutes to go.

The Bullets were on a roll. Out-manned, outnumbered, outran, out-jumped -- out-outed, for crying out loud! -- the Bullets had trailed the mighty 76ers by as many as 23 points as late as the third quarter. But now they were rallying, they were within seven points, they were standing there watching the amazing work of their No. 1 belly dancer, Big Jim Williamson.

They call Williamson "Supe," as in super, not soup, presumably, one suspects, because no liquid food has ever passed his lips. If Idaho wants a pro basketball player to sell its spuds, Big Jim is their man. And here he came, jiggling upcourt on the fast break, doing everything he wasn't supposed to. He's no ball-handler. He's no runner.

So he quit dribbling. He quit running. And on the point of a fast break in the last 3 1/2 minutes of a first-round NBA playoff game with his team seven points behind, what Big Jim did was absolutely crazy.

He came galumphing to a halt behind the three-point line, 26 feet from the hoop, and he leaned into his jumper, the way a seal leans to flip the beach ball to his trainer, and John Williamson did what makes him a pro. He shot the thing through the iron.

Well, that was that.

The crowd exploded in appreciation, for these Bullets, who had been so gawdawful early in the game, had not quit. They had taken it to the 76ers. Whatever the coach, Dick Motta, hadn't liked about his team this season, and there was a lot, he admired its attitidue on the court, "These guys never quit all year long," he said. "And they cold have."

Williamson had 14 points that last quarter, nine the last 6 1/2 minutes, including the last seven points that kept pulling the Bullets within four points. But that was that. Because Philadelphia is a superior team in almost every regard, it simply refused to blow a game it had won in the last two minutes of the first quarter.

In those two minutes, when the Bullets had in the game the five players they most want -- Elvin Hayes, Wes Unseld, Greg Ballard, Kevin Grevey and Kevin Porter -- two substitutes off the Philadelphia bench outscored the Bullets, 8-0, stretching the lead to 31-20.

By then a pattern had been established that wouldn't change until John Williamson became super, indeed. The 76ers were everywhere on defense. They seemed to have six men, even seven, against the Bullets' five. Hayes made only two of eight shots in that quarter, evidence of the relentless defense of Caldwell Jones and Bobby Jones.

Against the ever-running Sixers, the tiring Bullets were operating on forcing their work instead of letting it happen. John Wooden preached that you should be quick, but don't hurry. The Bullets were hurrying. The Bullets were hurrying. On a fast break Grevey flew around Darryl Dawkins, circled another Sixer and, off-balance, threw a beautiful lead pass 35 feet to Greg Ballard for a layup.

Nice work. But playoff victories are not built on such unrepeatable miracles. They are built on a team's basic skills. For the first time since 1969-70 the Bullets finished a season without winning a playoff game. That is no accident.

The fall is complete, from the mountaintop to a valley of shadows. It was a melancholy moment when the Bullets left the floor last night, 112-104 losers, taking with them only the bittersweet consolation that fills the night of lossers: they tried.

Of the 11 men who won the NBA championship for Washington two seasons ago, only five suited up last night. The man who is quick with his miracles, never hurrying, Bobby Dandridge, sat on the bench in street clothes, a chair away from Mitch Kupchak, a forlorn figure who may never play again.

It is hard, in fact, to figure which of these will ever play here again. Hayes says he wants to go to the new Dallas team, but Dallas has nothing to give for him. Unseld always hints of retirement, but he had his best year in five. Dandridge says "I don't know whether I want to come back or not," but he is under contract. Kupchak will try his repaired back again.

"I think it will be the end of an era," Grevey said in the locker room. "There are players in this room I won't see again."

Grevey ought to be back. There better. What the Bullets need desperately, and what Porter and Williamson and Larry Wright and Jim Clemons don't give them, is a big guard who can play defense. Motta is bright enough on the bench to be the third winningest coach even in the NBA, but he can't go out there and guard anybody.

"It's been a confusing season," Grevey said. "You didn't know who would be in uniform. There was dissension in this club. Frustrated people. It's been a sad season all the way around."

Why would Hayes, a 12-year veteran headed for the Hall of Fame, want to go to an expansion team, even if it is near his hometown? Dallas will be rebuilding from the start.

"The Bullets are rebulding, too," Hayes said.

Unseld, who brings majesty to his team, said as he always does at season's end, "There's a darn good chance I'm going to work," meaning in a real-life job.

"It's been a long season," Unseld said. "Not because of losing, but because we played like losers."

Now it's 106-102, the Sixers ahead, one minute to play. Williamson has the ball. Williamson, who is paid to shoot, not to have the ball. Williamson who came to town in a trade the Bullets should never have made, giving away the shining future of Roger Phegley for the flash of a few Williamson buckets today.

Williamson has the ball at midcourt. He is trapped. He cannot get rid of the ball. He is bouncing it. A no-no. And now Julius Erving, the Sixer's wonder, has taken Williamsonn's dribble. He's gone. The Doc is gone. Flying the other way for a layup and a six-point lead with 51 seconds to play.

Bye-bye, era.