Late in the seventh game of their 1976 National Basketball Association playoff series against the Cleveland Cavaliers, the Washington Bullets were trying to run out the clock when guard Clem Haskins, a usually heady player, called time out because he noticed his shoelace was untied. Following the break, the Bullets were unable to inbound the ball and the Cavaliers scored the winning basket on the next possession.

A couple of seasons later, the Bullets were having their hands full with the San Antonio Spurs in the Eastern Conference semifinals. It was Game 6 and Washington needed to win to avert a seventh game. Suddenly, Capital Centre went half-dark. Many of the lights went out for nearly 20 minutes. "They were really kicking our tails up until then," General Manager Bob Ferry recalls. "But after the lights came back on it was like we couldn't do anything wrong." The Bullets came on to win that game, advance to the conference final, beat the 76ers in six games, too, and go on to the NBA championship over Seattle in seven.

So, it is not surprising to hear Ferry say that the unknown often can be important in a playoff series. Of course, he also knows that an outstanding big man probably is more important.

Washington's hopes in the playoffs -- which open tonight at the Spectrum in Philadelphia against the 76ers -- probably will involve a little of both. Bolstered by the return of center Jeff Ruland, the Bullets enter the best-of-five series "about as good as we can be," according to Coach Gene Shue.

"If we play well, I think we have a chance. We've been doing well. All things are positive," says Shue, who often appeared frustrated before the final week of the season. During the last seven days, though, the Bullets won three of five games and played well even in losses to Detroit and Milwaukee.

That was without Ruland, who will attempt to make it back from more than two months out because of a strained right shoulder.

To stay in shape, Ruland ran every day. He dropped about 10 pounds from his usual 270. Ruland says the weight loss will make him quicker and he'll still have enough strength to try to fend off Philadelphia's massive Moses Malone.

For those looking for an offbeat sign that might have a bearing on the series, try the off-the-court contributions of both Ruland and guard Frank Johnson, also activated for the postseason. The two generate the bulk of the Bullets' locker room humor and the team leadership as well, qualities that were spotty during the team's slide to mediocrity over the last two months.

"Frank isn't nearly as important in those aspects of the game as I am. In fact, we just try to omit thinking of him whenever we can," Ruland joked after the Bullets' practice Monday. "No, really, it's good that we both are back. At this time of year we should be together as a team."

Team play, both offensively and defensively, is the key to any success Washington might have against the 76ers. In the last two days, the team drilled incessantly, looking for measures to counteract both the Sixers' tendency to isolate individual players on offense and the defensive pressure generated by the Philadelphia back court.

To deal with the latter, Shue is considering replacing forward Greg Ballard in the starting lineup with Darren Daye. The reasoning for the move is twofold:

First, having the 6-foot-8 Daye bring the ball upcourt could counter the pressure brought to bear by Maurice Cheeks, Clint Richardson, et al., and also would make 76ers forward Julius Erving work harder. This ploy was exercised to perfection by the New Jersey Nets in their five-game upset of the then defending champion 76ers in last season's playoffs.

Second, having a good outside shooter like Daye in the lineup should provide a necessary outlet for Ruland, who undoubtedly will be double-teamed.

Another important factor for the Bullets will be the play of point guard Gus Williams. As he compiled a team-leading 20 points per game, Williams' shooting percentage fluctuated wildly from his season figure of 43 percent.

He came on in the last two regular-season games to average 26 points on 61 percent shooting.

Williams figures as especially valuable in the playoffs because he is the only member of the Bullets other than Ballard to play on a championship team, winning with the Seattle SuperSonics over Washington in 1979. In addition, Williams never has missed a spot in the playoffs during his nine NBA seasons.

"Playing 82 games and then calling it a season isn't what it's all about," Williams said. "This time of year is what you work so hard to achieve. If I went through 82 games without any statistics but the team I was on won the championship, then it would be a great season."