Tough as he knew it would be for anyone else to digest, Kevin Grevey still offered his Hamburger Theory for rediscovering how to score. And logic got kicked so often by both teams in game three of the playoffs tonight that we might as well listen as he says.

"I almost always don't eat anything after 1 o'clock on game days, byt today I had a burger. And felt sluggish, sort of dizzy. And then the third quarter I seemed to get it out of my system."

Grevey and every Bullet other than Elvin Hayes shot horribly the first half-but walked off the court, heads shaking, with a three-point lead.

"Playing frustrated" Grevey called it. "We wanted to push it up quickly - and maybe we forced the shots. And when you miss two or three shots (the Bullets missed 21 of their first 28 shots) you think about it a little bit.

"And we had no one to go to (even Hayes was erratic early). Nights like this you just have to keep running, try to play yourself out of it."

Before the fourth quarter of the 89-77 Bullet victory, nobody was more frustrated than Grevey. Without a pre-game food alibi, he had shot poorly enough to be benched during the important minutes of game two in Washington Tuesday.

He was one for seven the first half tonight, then shot an air ball early in the second half and missed a layup Hayes rebounded for a basket. Then the drought ended. He was open from the left baseline and the shot dropped.

"That felt horrible, too," he said. "Nothing really felt right 'till the fourth quarter."

Then everything felt right.

"Everybody said I hadn't been getting high enough off the floor earlier," he said. "Elvin and Larry (Wright) also said I'd been looking for a defender as I was getting into the shot instead of just looking at the hoop. And when they started going in I kept wanting the ball more."

From the final moments of the third quarter until victory was assured, Grevey missed just one shot in six tries-and fed Wes Unseld for an open layup when the Hawks were forced to pay attention to him.

Grevey scored the points that all but iced the game, hitting with three seconds left on the shot clock for an eight-point lead with 3 1/2 minutes left and a long jumper a minute later to maintain that margin.

At last, the Bullets had someone to keep the Hawks defenders from mauling their frontcourt players. And Atlanta Coach Hubie Brown saw a reason for Washington's regaining the edge in the series that failed to materialize in the stat sheet.

"I just finished talking for 10 minutes to my team about Elvin Hayes," he said, about 15 minutes after the game. "When the game got tough, we had two guys go in the tank.

"I'm talking about from the top of the circle to the top of the circle, where you gut it out. Elvin Hayes only had three points the fourth quarter, but he went board to board.

"He would double-team our man with the ball. And then (when the shot missed) he would beat the guy he left for the rebound. Elvin Hayes iced our rears. He was absolutely intimidating.

"And (Mitch) Kupchak kicked our small forward's rear by keeping the ball alive. (John) Drew was six for 18, (Dan) Roundfield was five for 19, (Eddie) Johnson was four or 12. Where are we going with that?

"They outscored us in the 'garbage game.' That's fast breaks and second shots. They outscored us there, 53-35. They had the luxury of knowing they would get the boards (although Brown failed to notice his Hawks had 13 more rebounds.

"The first guy would release and the first pass would be beyond the 28-foot line. Unseld gets that ball out there like a rocket."

Bobby Dandridge, who was nearly as cold as Grevey early, agreed.

"We were able to take over," he said, "because we kept pushing and kept working on the things we'd been trying to do all game. We used our hands better, came up with more loose balls, took over on the boards.

"The game started to open up in the fourth quarter. That's when the strong team can take command. And maybe I'd been going one on one too much (the first two games). Everybody works harder if they' involved in the offense." CAPTION: Picture, Owner Ted Turner cheers for Hawks while Georgia Gov. George Busbee (right) resorts to fist pounding. UPI