At this stage of the game, down by 2-0 to the Boston Celtics in the best-of-seven NBA championship series, the Houston Rockets know that talk of mounting a comeback would sound hollow, so they don't try. Even the fact that the next three games of the series are scheduled to be played here at the Summit does little to inspire them.

"Yeah, they've got us struggling now," said guard Mitchell Wiggins. "But I guess if we're gonna struggle, it's better to do it at home than at someplace else."

Of course, the Celtics have stumbled only once on their home floor throughout the 1985-86 season; the victories in Games 1 and 2 of the series stretched their winning streak at Boston Garden to 40 and their overall mark there to 48-1. But the Rockets have been almost as invincible at the Summit, winning their first 20 home contests and finishing the regular season with a 36-5 home record.

The team has won seven straight games here during the playoffs, including a pair over the Los Angeles Lakers that put the defending champions on the ropes, with the knockout punch delivered three days later in Game 5 of the Western Conference final. The Rockets aren't in nearly as deep; should they win Sunday (3:30 p.m. EDT) or in Game 4 Tuesday, they would be rewarded with another home game two nights later. That doesn't appear to be registering, however, as the Rockets' words come out passive and dispirited.

But their coach, Bill Fitch, was more upbeat. "If you give us just one win, anything can can happen," he said. In his next sentence, though, Fitch's fervor appeared to have faded: "One of our losses at home was to Boston, so they'll the Celtics have some comfort in that."

There's so much more for Boston to feel comfortable with. First there's Larry Bird. Working on the right side of the court in a one-man isolation formation, the three-time NBA most valuable player has made a shambles of Houston's defense, its players unsure when and if they should double-team the forward. Decisions the Rockets have made so far have been incorrect and have left forward Rodney McCray exposed.

"Rodney always gets the tough assignments," said center/forward Ralph Sampson. "He guards the James Worthys, the Alex Englishes. . . . Bird is probably 90 percent of their game plan. But he's played Larry tough, I know he can play him tougher."

McCray isn't sure that that's the right tact. "You have to give up something on defense," he said. "Maybe we should make someone else beat us."

On the defensive end the Celtics have had their way as well, partly because of their ability to slow down the Rockets' running game. In a half-court situation, Boston has benefited from poor shooting by the Houston back court. In the opening two contests, starting guards Lewis Lloyd and Robert Reid were 16 for 39 from the floor.

That contrasts mightily with the 70 points scored by Boston starters Danny Ainge and Dennis Johnson, one point less than all six Rockets guards.

"A lot of times [it's because] the guards aren't involved with the offense," Ainge said of Houston's back court troubles. "Lewis Lloyd is best in the full-court game, Robert Reid is best in the full-court game. But we've taken them out of that and everybody knows that their whole half-court offense is revolved around Ralph and Akeem [Olajuwon]."

The duo combined for 39 points and 18 rebounds in Game 2 but there was little help from anyone else in the 117-95 loss; McCray, with 10 points, was the only other Rocket in double figures.

Near the close of practice, the normally acerbic Fitch turned philosophic when asked if his squad was mad at its predicament.

"Mad as in insane or mad as in angry?" he asked. "I hope not. Anger is an emotion that blows out the candle of intelligence."