Bernie Bickerstaff, the Bullets' assistant coach, called it a "horror movie," and he said if the Bullets don't learn their lesson from watching it, their playoff series with Atlanta could turn into a nightmare.

"It was awful, horrible," Bickerstaff said of the films of the Bullets' 107-99 loss to Atlanta Tuesday night that knotted the NBA Eastern Conference semifinal series at one game apiece.

"I don't think we've played that bad in I don't know how long," he said. "There was no movement, no intensity, no desire. We just came out and walked through our plays. We can't just show up and expect to win this series."

The players sat in on the first and probably only viewing of the game movie, then went only and practiced "harder than we have moved in awhile," according to Coach Dick Motta. "I just hope they can keep that kind of movement in games."

The Bullets face a most difficult task: to regain the home-court advantage in the best-of-seven series, they must split the next two games in Atlanta, where the Hawks have won 17 straight.

Washington has not played anywhere near its capabilities in its two playoff games.No one is quite sure why, although all sorts of theories have been offered: late-season injuries are still slowing the team, the players are taking Atlanta too lightly or the motivation of last season, when the Bullets won the world title, is missing.

But the coaches and players think there are move concrete reasons. From their film reviewing, the consensus seemed to be that the Bullets have to:

Generate a better running game instead of trying to scratch it out with Atlanta every time down the court. The need to fastbreak is especially important when the Hawks go to their tall front court of Dan Roundfield, Tree Rollins and Tom McMillen, a strong-rebounding but slowfooted trio.

Rebound much more consistently instead of letting the Hawks do so well on the offensive boards. Without defensive rebounds, fast breaks are impossible.

Execute their offense more effectively, getting scoring from everyone instead of mainly Bog Dandridge and Elvin Hayes. So far, the attack has concentrated on working the ball inside, but if Atlanta continues to sag as it did in game two, some accurate outside shooting will be needed to loosen up the defense.

Receive more help from the bench, which was a major reason the Bullets compiled the league's best regular-season record. Atlanta has received quality performances from nine players in the two games, while the Washington reserves, except for Larry Wright, have been spotty. If the team's from-court starters continue to get into foul trouble, then Mitch Kupchak especially needs to take up some of the slack.

Play with much more desire and hustle. Atlanta is a talented squad that cannot be defeated with mediocre efforts. If the Bullets did not regard the Hawks' challenge properly before, it seems unlikely that will be the case now.

"I think the running game is our No. 1 priority," Dandrige said. "We've got to start moving better and get the ball up the court.

"And that means we have to do a better job rebounding. If we don't have the ball, we can't move with it. The only time we've really looked good in the series was in the fourth quarter of the first game, when we kept beating them down the court.

"If they want to play those three big guys at the same time, we have to be aware of it immediately and know what we want to do. We've got to use our speed and quickness on them when they are that big."

Although critics were quick to point to Hayes' 10-point effort in game two as a main reason for the team's downfall, Dandridge said it was unfair "to blame one player for what was a squad-wide problem.

"Maybe we all aren't working as hard as we should for shots. And maybe we all aren't setting screens and picks as tough as necessary to free others for shots.

"For some reason, we don't seem to be as confortable and as ready to play as a team as we should be. We really haven't executed our offense that well all year, but we have played together as a team and we've run and rebounded well. We start doing those things and we will be okay."

Guard Kevin Grevey would like to see the team "push the ball up even when we don't have the break. Even when Atlanta scores, we should hustle it up. As it is now, we are running 10 seconds off the clock every time before we get into our offense.

"They are hungry and they are coming after us. Maybe we have to get in there and rattle them with a few picks. By now, we know they've got a really good team. We have to respect them."

Although deeply troubled by his team's uninspired performances, Motta tried to rationalize the defeat.

"We can't play much worse, so we have to have a lot of good basketball in us," Motta said.

"For some reason, we just don't want to do things easy. We had the home-court advantage, and now that's been taken away from us. But we got into deep trouble against Seattle last year and dug our way out, so I don't see why we can't now."

The major unknown factor is whether the Bullets have been sufficiently disturbed by events in the series to begin exhibiting the kind of overwhelming team efforts that charactized many of their regular-season triumps.

Mota thinks the Bullets will respond, because "this is a proud bunch." CAPTION: Picture, Hubie Brown: "He screams, cajoles, flatters, threatens, demands, praises." UPI