Who would have predicted three weeks go that a change in coaches for the Seattle SuperSonics would have more effect on the National Basketball Association than the return of Kareem Abdul-Jabbar to the Los Angeles Lakers?

But that is what has occurred is the mixed-up NBA Western Division where only Portland is keeping things from becoming completely unpredictable.

While the Trail Blazers threaten to break the league mark for fewest losses in a season (13), the bakers are looking up from the bottom of the division, the Super-Sonics are playing like title contenders, the Phoenix Suns are treading water in second place despite the NBA's third-best record and Golden State is still trying to win its second road game of the season.

This is hardly how the division was supposed to behave. Los Angles, thanks to some good off-season trades and lavish spending by owner Jack Kent Cooke, was going to challenge Portland game by game the enttire season. Phoenix and Golden State were potential 500 teams while Seattle looked like a mediocre club at best.

It hasn't worked out that way, mainly because of the performances of the division's odd couple, Los Angeles and Seattle.

The Lakers have the largest payroll in the league. and they keep adding more talent (Adrain Dantley being the latest addition). But not even Cooke's millions could prevent the injuries, personality conflicts and fights that have kept his team from being consistent.

Seattle, meanwhile, has won nine of its last 10 games under new coach Lenny Wilkens. The mixture of veteran discards and young players are blending much like the NBA's other rag-tag outfit, the Atlanta Hawks.

"Hey, we could make the play-offs," said Seattle's Fred Brown, a verteran who probably should know better than to make rash statements. But when things are going right. as they are for the SuperSonics, who once had the second-worst record in the league, you can afford to be aptimistic.

Los Angeles figures to have a better chance of making the playoffs, even after its struggling start. All coach Jerry West wants is some time. "We need to play with each other for awhile," he said. "WIth everything that has gone wrong, it's like starting over all the time."

The Laker's difficulties began in the opening game when Abdul-Jabbar punched Milwaukee's Kent Benson and broke his hand in the process. He missed the next 21 games and the Lakers struggled to an (SECTION) 13 record.

Since he returned, they have won only four of eight games, mainly because even his domisating presence couldn't offset West's other headaches.

During the opening months of the season, the Laker coach lost highly regarded rookies Kenny Carr (broken foot) and Brad Davis (broken hand) and veteran Don Chaney. Jamaal Wilkes was slowed by a virus and West was trying to blend a team that now has only four players left from the squad that compiled the NBA's best record last year.

Then when things seemed to be settling down, Kermit Washington punched RUdy TOmjanovich last week and was suspended for two months. The Lakers quickly pulled off a trade for Dantley and wound up with a starting unit that has only one survivor from last season, Abdul-Jabbar.

It hasn't been easy for West, the former All-Universe guard who made such an impressive coaching debut last year. During one East Coast road trip, he got so many calls from Cooke asking what was going wrong that he told one writer: "I don't have to put up with this. It's not worth it."

Cooke was upset because he felt the Lakers had enough talent, even without Abdul-jabbar, to do better than they did during his absence. And his conviction grew even straonger one rookie center James Edwards demostrated he was a more than adequate replacement.

NBA sources say that part of the problem was Wilkes, the exfree agent from Golden State, who, the Lakers felt, did not carry enough of the burden during those troubled early weeks.

The team West now puts on the floor is overwhelming on offense, at least up front. With Dantley and WIlkes, teams can't afford to double on Abdul-Jabbar or the forwards will be free to roam and score. Dantley will benefit from being able to go one-on-one more than he could in the past, although he probably will have to be contest with fewer shots.

The Lakers' achilles heel, however, may be the guards. Rookie Norm Nixon has been inconsistent, although a promising play-maker. Veteran Lou Hudson, who has lost some quickness, is now his reunning mate, replacing Earl Tatum, who was dealt to Indiana in the Dantley trade. Their replacements, Ernie DiGregorio and Chaney, are either slow, old or both.

Wilkens would be happy if his club continues just as it is. From a grumbling, unhappy bunch that was straining under ex-coach Bob Hopkins' tight rein, the Sonics now are singing in the locker room and are as optimistic as any team with a 14-18 record can be.

The difference, the players say, is Wilkens, who coached the SOnics before Bill RUssell and then wound up as director of player personnel before replaceing Hopkins.

Wilkens was responsible for most of the deals that brought together this current Sonic team.To get the most out of it, he has stopped critizing players in public (something Hopkins did frequently), he has let them fast break (Hopkins wanted to run patterns most of the time) and he has rearranged the starting lineup, giving almost everyone on the club playing time (Hoppkins preferred a set line-up.)

In preseason, Seattle started Mike Green at center. He is now with San Antonio and Marvin Webster, playing like his nick-name (the Human Eraser) is the driving force behind the SOnic surge. He has averaged 17 points and 16 rebounds in the last five games and is swatting away shots like a young Abdul-Jabbar.

To give Webster more rebounding help, WIlkens put 6-11 rookie Jack Sikma (from Illinois Wesleyan) at forward instead of veteran Paul Silas, who is better as a spot player. And he replaced shooter Bruce Seals with John Johnson, a better defensice player who seems to have found a home with the SOnics after being traded twice this season.

When Browns hurt a knee, Wilkens moved in second-year man Dennis Johson, a fine leaper who also goes to the basket.And ex-free agent Gus WIlliams has given the team more scoring power as a playmaker instead of SLick Watts.

What is surprising about the Seattle situation is that Wilkens has not yet decided whether he wants to coach next year, even with his current success.

"I'll make up my mind at the end of the year," he said. "Right now, this is too much fun to be thinking so far ahead."