First he threw chalk against a blackboard. Then he yelled. And Finally Nevada - Las Vegas coach JeJrry Tarkanian told his team at halftime that he was going to the final four anyway. It'd be nice if you came along too."

The Rebels agreed. They swarmed out in the second half and blew away Idaho State, 107-90, to win the NCAA West Regional title. Now Tarkanian will have plenty of company on his plane flight Thursday to Atlanta, site of the final games of the NCAA Tournament.

"I don't think I've ever been thta upset before with them at halftime," said Tarkanian. "The seniors have been with me for four years and this is the biggest game they've had and they were sleep-walking out there."

What had Tarkanian especially upset in the locker room was the scoreboard which read: Idaho State 52, Las Vegas 15.

He already knew that both North Carolina and North Carolina-Charlotte had registered playoff upsets earlier in the day and he didn't want Idaho State to continue the trend. Neither, as it turned out, did his team.

The Rebels caused 11 turnovers and shot 56 per cent in the final half (compared to 43 per cent in the opening period) and outscored the Behgals, 31-15, in the first 12 minutes after intermission.

This is the seventh squad that Tarkanian has had in the NCAA Tournament, but the first to get past the regionals. Twice before, he had lost in the regional final to UCLA.

"Maybe that makes this one my biggest win," said Tarkanian. "I've always wanted to get to the final four. It's the dream of every coach."

For a while, Idaho State seemed capable of turning his hopes into a nightmare. The Bengals, who upset UCLA Thursday night to deprive Las Vegas of a much-desired shot at the Bruins, played heady basketball for a half. Then they tired, started missing shots and slowly disintegrated.

"I could see we were tired at half-time," said Idaho State coach Jim Killingsworth. "But I didn't want to tell my players. "You don't break down against a good club and still come out a winner."

But for 20 minutes, things were going Killingsworth's way. The Bengals even jumped to a 48-41 lead at one point, forcin Tarkanian to call a rare time-out.

Then Las Vegas' vast edge in depth, talent experience and quickness began eliminating whatever advantage daho State had held through emotion. And Kittingsworth couldn't equal Tarkanian's halftime dramatics, either.

"I've seen him madder," said forward Glenn Gondrezick about Tarkenian's tirade. "He had kicked over blackboards before. But he got the point across to us. We weren't playing with any intensity. We didn't want it bad enought."

Tarkanian's talk produced instant results. After an Odaho State foul shot, Las Vegas ran off eight quick points. In the midst of that spurt, two fouls - an apparent charge by Vegas' Sam Smith that wasn't called and an elbowing foul on Idaho State center Steve Hayes that was - took the growl out of the Bengals.

Vegas continued to pour it on its weakening opponent. A 16-footer by Robert Smith, a 10-footer by Robert Smith, a 10-footer by Eddie Owens a 14-footer by Tony Smith, then another Vegas was in front, 71-59.

"More than anything else, including the shooting and the turnovers, we were hurt by not being able to get all five people between the ball and bucket," said Killingsworth. "In the first half, we had a lot of help on the guy with the ball. In the second half, we didn't have the defensive support and got into a lot of on-on-one situations."

And, as Turkanian said afterward, he has a one-on-one team that "has to play with intensity on defense and has to run. If we don't, anyone can beat us, anyone."

Just us in their victory last week over San Francisco, defense did play a large part in this Vegas triumph, especially the job Moffett and Lewis Brown did on the 7-foot Hayes, Idaho State's top scorer.

Hayes finishes with 16 points, but more telling was the low number of shots he took (10) and his inability to break free consistently near the basket.

"He became my man," said Moffett. "I kept as close to him as I could, and made sure the ball never got to him. I wanted to play behind him, so I could block some shots, but coach made me front him. I guess he knows best."

Tarkanian also knew best in the way he subsituted. He got a combined 42 points from reserves Reggie Theus, Tony Smith and Lewis Brown and kept his players fresh in the process. Dwens led the Rebels with 24 points.

"We've worked our butts off for four years, listening to him yell," said Owens, who was one of five blue chippers Tarkanian recruited in his first year at Las Vegas. "But it was good that he yelled at us again. Playing Idaho State and all, it was a letdown for a lot of us."

Five munutes later, the advantage had grown to 80-67. Vegas had made 15 of its first 25 shots while Idaho State, a 51 per cent shooting team in the opening half, convered only six of 15 attempts. By now, he Bengals were struggling to get the ball over halfcourt against Las Vegas' double-eaming tactics.

What Vegas had wanted was a shot at UCLA, the perennial kings of the West Regional. Now the Rebels can settle for a shot at the national title, which means first they have to get past North Carolina Saturday afternoon in Atlanta.

And when would Tarkanian start thinking about the Tar Heels? "Not until tomorrow," he said before adding "probably."

Then he laughed. "Geez, I'd like to savor this one a little, North Carolina is so solid. And I never know about my team. They really are a funny bunch."