The Bullets begin their final quest for their first NBA championship today, convinced the best-of-seven series against the Seattle SuperSonics could be determined by the outcome of today's opening game.

"It may not be that important if we lose," said Bullet Coach Dick Motta, "but it's a must-win game for Seattle."

If the Sonics lose this 3 p.m. contest (WTOP-TP-9; WTOP radio-1500), they face the prospect of falling behind, 3-0, in the series before returning home on June 2 for game four. Games two and three will be played Thursday and next Sunday at Capital Centre where the Bullets think they can handle Seattle.

"There's no question there is more pressure on them," said forward Bob Dandridge. "Even if we lose, it wouldn't be bad as long as we don't get blown out, or our execution breaks down. But if they lose, they've lost their home-count advantage and they could fall far behind quickly in the series."

The Bullets learned the hard way in the 1975 final what losing the first home game can mean.They were upset by Golden State in the opener, then lost the next two games on the West Coast and wound up being swept in the series, 4-0. They also fell in the 1971 final to Milwaukee, 4-0.

Wes Unseld is the only player who appeared in both of those series. He is so intent in avoiding another sweep that the 10-year NBA veteran even ran on his own before practices last week.

The Sonics won 70 percent of their games over the last two-thirds of the season. They are favored by the oddsmakers to capture the series on the basis of that home-court advantage. They have won 20 straight home games since losing to the Bullets in the Seattle Coliseum Feb. 8.

The Bullets, however, overcame home-court advantages against San Antonio and Philadelphia to reach this round, their third appearance in the finals in the history of the franchise.

Neither of these evenly matches teams were supposed to get this far in the playoffs. Both will try to gain the championship with different styles.

The Bullets will pound away inside with Unseld, Elvin Hayes and Dandridge, who together represent 29 years of professional experience. Seattle will depend on its shooting guards, running game and No. 2-ranked defense.

Washington's approach - a strong inside game centered around experienced players - is considered the standard way for NBA clubs to win the title instead of relying on outside shooting as does Seattle. But the Sonics have defied the odds ever since Lenny Wilkens took over as coach in November. He has parlayed youth, enthusiasm and the dominating presence of center Marvin Webster into a winning combination.

Unseld and Webster provide one of the series' most important matchups. The Bullets believe Unseld, who weights 30 pounds more than Webster, can wear him down with his characteristic physical play. If Webster tires or gets into foul problems, Seattle, which does not have a true back up center, will have a problem controlling Washington around the basket.

Webster is expected to guard Unseld defensively. However, Wilkens has not ruled out putting him on Hayes and letting rookie Jack Sikma try his luck with Unseld, instead of going against Hayes.

A Hayes-Webster matchup would be intriguing. Hayes says he can score against Webster in a one-on-one duel. Motta believes if Webster has to spend his time concentrating on Hayes, Seattle will be giving up rebounding and shot-blocking strength.

The matchup also would benefit Dandridge. As long as Webster is stationed in the middle, Dandridge will maneuver around the perimeter against John Johnson. But if Webster moves to Hayes, Dandridge will work inside more, where he says he has been successful in the past against Johnson.

The Bullets need the same type of series from dandridge as he produced against Julius Erving and Philadelphia. Small forward has been the Sonics' major weakness this season, with Johnson acting more as a third guard than a frontcourt player in many games. If he can't handle Dandridge, then Seattle may switch to guard Dennis Johnson, who controlled Denver's David Thompson.

"We've got to cut them off inside," said Wilkens. "We can't let them get the ball where they want to in there."

Wilkens is concerned about Sikma's tendency to get into foul trouble. His replacement is veteran Paul Silas, a master offensive rebounder who has not had much luck guarding Hayes in the past. Motta said he would be surprised if either Sikma or Silas could contain Hayes.

Seattle expects a physical, aggressive series from the Bullets. Webster says "as a team, we can pound too. We like to keep pressure on the other team. There is no question there will be plenty of pounding, but we can play that way if we have to."

But the Sonics would much prefer to have a quick-paced, free-flowing game where they could run fastbreaks and put up shots before the Bullets can get back on defense.

For them to achieve these aims, they need to equalize Washington's rebounding strength and receive outstanding efforts from their trio of guards, Gus Williams, Fred Brown and Dennis Johnson.

Williams is firey, quick and a streak jump shooter who can ignite the Sonics with his scoring. Brown is one of the league's premier sixth men, a long-range marksman who also is a good defender. Johnson is an underrated player who rebounds well, handles the ball competently and is a decent medium-range shooter.

Bullet guard Tom Henderson will be matched against Williams in what might be the Bullet's most pivotal pairing. Kevin Grevey, whose outside shooting takes pressure off the Bullets' inside game, will go against defensive ace Johnson. When Brown comes in, Motta will counter with either Larry Wright or Charles Johnson.

Motta expects Seattle to "push the ball up the court every chance they get. Lenny always has liked that style. It's up to us to get back on defense, rebound offensively and not let them get untracked. We've been able to control the tempo so far in the playoffs and we want to continue that now."