Mavericks Finally Get Their No. 1 Men : Pro basketball: Team with a 4-50 record signs its top draft choice Jim Jackson for $20 million and hires Quinn Buckner as coach for next season.

The Dallas Mavericks, who went six weeks without a head coach and all season without their No. 1 draft choice, landed both Thursday, hiring Quinn Buckner and signing Jim Jackson.

Buckner, now an NBC commentator, will take over next season. Interim Coach Gar Heard will remain in charge for the rest of the season.

Jackson will report immediately, breaking his vow never to play for the Mavericks and to go through the draft again after they failed to meet his negotiations deadline last week.

He and the team reached an impasse early in negotiations, Jackson asking for a six-year deal, the Mavericks holding the line at four years. Then last week, the team came up with the six-year, $20-million deal Jackson had sought.

“Surprises are everywhere,” General Manager Norm Sonju said.

Two weeks ago, Sonju caused a flap by suggesting that the Mavericks write Jackson off, calling him “our Len Bias,” a reference to the Celtics’ No. 1 pick in 1986 who died of a cocaine overdose the night of the draft.

Emotions had been running high since Jackson, the fourth pick in the draft and a prospect compared by admirers to Oscar Robertson, arrived at the impasse with Maverick owner Donald Carter.

The team worked out a deal--to the Lakers in a three-way transaction that would have sent Vlade Divac to Milwaukee--but Jackson turned it down. Because of salary cap restrictions, the Lakers could offer only Divac’s present salary, $942,000, but offered a long-term deal with 30% annual raises. They also offered a one-year deal for the minimum salary, $190,000, that would have made Jackson a restricted free agent, assuring him that they would take care of him after that. Jackson said no.

“I’m sorry it took so long, but I’m looking forward to the future,” Jackson said at a news conference in Dallas. “They want to build with youth. I’m young.”

Jackson’s contract includes this season, for which he will be paid a reported $3.6 million, which includes a $1-million bonus, even though he will play in 28 games at most. He is expected to play only a little tonight in a home game against Houston.

Buckner was offered the job shortly after coach Richie Adubato was fired Jan. 13. The first of Indiana Coach Bob Knight’s players to coach in the NBA, Buckner called the Maverick job a tremendous opportunity.

He might have said they have nowhere to go but up. Currently 4-50 and on a 12-game losing streak, the Mavericks’ .071 percentage is worse than that of the 1972-73 Philadelphia 76ers, who set the NBA record for futility at 9-73 (.110).