Frank Layden wanted to walk away in June, after the Jazz's best season ever. He would have stepped down after this season, at the latest.

So the only surprise about his decision to leave coaching Friday was the timing, 17 games into a promising season. Then again, we should know by now to expect anything from Layden."It was a big shock," said Jazz guard Bobby Hansen, "but that's Frank. It's vintage Frank Layden; he never really does anything by the book."

After almost exactly seven years on the Jazz bench, Layden leaves his chair to Jerry Sloan, his assistant of four-plus seasons. Layden will have the title of team president, working as basketball adviser to general manager David Checketts, who came up with the idea of giving up part of his title to Layden but will still run the day-to-day business and basketball operation.

Sloan will receive a new contract; Checketts says only that the deal will be long enough "to give Jerry some confidence."

The Jazz were informed of the change Friday morning, when they reported for the shootaround in advance of that night's game against Dallas. Sloan himself knew of Layden's plans only Thursday, when he was handed the job.

Sloan's old position is left vacant; Scott Layden chose to remain as the No. 2 assistant coach and player personnel director, and David Fredman is the No. 3 assistant coach/scout. The obvious choice for a No. 1 assistant is Phil Johnson, who assisted Sloan in Chicago and Layden in Utah before becoming the Kings' head coach. He's now a Sacramento assistant, under contract through next season. If he is not available this season, Scott Layden

will work as the interim No. 1 assistant.

Why did Layden want to leave coaching? "The interesting thing this year is that we're winning . . . but he was tired, he was burned out," said Checketts.

Borrowing a quote from Jazz consultant Jack Gardner, Layden said, "After a while, the ball dribbles you."

Layden took the Jazz from being an NBA doormat to a championship contender last season, but the pressure is greater than ever to take the next step. "It's a young man's game," said Layden, 56, who has stayed with one NBA team longer than all but two active coaches, Denver's Doug Moe and the Lakers' Pat Riley. "You pay a big price in coaching. I loved a lot of it, but there was a lot of it I didn't like."

Travel, referees and, yes, even radio talk shows took a toll on Layden, who was booed regularly in the Salt Palace last season. "It was like I got dumb every other month," he noted. All that changed when Layden and the Jazz took the Lakers to seven games in the Western Conference semifinals, but Layden was convinced by Checketts and owner Larry Miller to come back for one last year.

That decision came in a meeting in early June, when the Jazz received inquiries about Layden from the expansion Miami Heat. "Here I was looking to get out of coaching," Layden mused Friday, "and they were looking to hire me."

Friday, Miami general manager Lewis Shaffel, a friend and fellow Brooklyn native who'd also tried to hire him in New Jersey in 1985, said of Layden's move, "It caught me totally by surprise."

The idea that he would have the most pleasant team makeup of his career and possibly challenge for an NBA title brought Layden back this season. So why is Layden leaving right now? He'd had enough, as he discovered in October.

"When I got to training camp, I said to myself, `What am I doing?"'

The only public clue that Layden was fed up came after a win over Houston on Nov. 23, when he was so upset about the officiating that he closed his office door to reporters after the game _ but he'd done that before.

He started thinking seriously about stepping down after a Nov. 29 loss at Seattle. The following night, after a win over Chicago, he met with Miller and Checketts for two hours in his office adjacent to the Jazz locker room and asked if he could quit, saying, "Even when we lost, this used to be fun." Miller's response was, "Let's think about this a little."

When Layden called Checketts from Oakland Tuesday and re-emphasized his stance, Checketts knew he was completely serious, and Layden met again Thursday with Checketts and Miller. Said Miller, "When he brought it up again in a completely unemotional setting, I decided I should give him the professional courtesy to do it."

The move gives the Jazz organization a chain of command similar to that of the Boston Celtics; legendary former coach Red Auerbach has the title of president and Jan Volk runs the team as general manager. Boston also has former coach K.C. Jones as the vice-president of basketball operations, which was Layden's most recent title with the Jazz.

A former Atlanta Hawks assistant, Layden joined the Jazz in 1979-80 when the franchise moved from New Orleans to Utah and owner Sam Battistone offered Layden the job of coach or general manager. He chose general manager, but ended up taking both jobs Dec. 10, 1981, when Tom Nissalke was fired. He stayed on through the next season mostly because the dual role saved the team money, and the Jazz improved enough that Battistone awarded Layden a 10-year contract.

The Jazz really took off after that, winning the Midwest Division championship in 1983-84 when Layden was named the NBA Coach of the Year and Executive of the Year. "He really made the most of a tough situation, and it was really good to watch it develop," said Johnson, his former assistant.

The deal was reworked in May 1986; five years remain, during which Layden says, "I want to relax and be a guru for a while."