Whoever coined the phrase “the rich only get richer” could have been talking about the NBA.

Just look at what the top five teams in the West have done:

The Spurs added two new starters and a couple of key reserves to a team that won the title. The Lakers added a pair of future Hall of Famers to play alongside Kobe Bryant and Shaquille O’Neal.

The Mavericks brought in a pair of 20-point scorers, the Timberwolves surrounded Kevin Garnett with plenty of new talent, and the Kings acquired an All-Star center.

“The top teams are still the top teams – San Antonio, L.A., Dallas, Minnesota’s real good, Portland’s good, Sacramento,” new Houston Rockets coach Jeff Van Gundy said. “If you start naming them, and you’re not one of those coaches, you start getting scared because you have to play them all four times.”

The West is so good that the ninth, 10th and 11th best teams in the conference could be playoff-caliber teams in the East. Only one Eastern Conference team, the Detroit Pistons, won 50 games last season, whereas the West had six members of the 50-win club.

And while many of the top teams in the West improved by adding better players, their counterparts in the East often made their biggest changes at the top.

Of the eight Eastern teams that went to the playoffs, five of them – Detroit, Indiana, Milwaukee, New Orleans and Philadelphia – changed head coaches.

The Cavaliers, Clippers, Wizards, Rockets and Raptors also changed head coaches in one of the most turbulent offseasons ever.

Of course, the summer’s biggest offcourt news was the rape allegation against Bryant, one of the most visible superstars of the post-Michael Jordan era. Bryant, facing up to life in prison if convicted, is trying to proceed with his basketball career when not otherwise required to be in a Colorado courtroom.

“I think for most basketball fans, certainly a prime matter of consideration is to see how Karl and Gary mix with the existing stars on the Lakers and where that goes,” NBA deputy commissioner Russ Granik said, referring to Malone and Payton.

“Once the ball gets thrown up, except on occasional days, that will be the bigger story with the Lakers.”

The NBA begins its 57th season Tuesday with the Lakers headlining opening night.

Their first opponent will be the reloaded Dallas Mavericks, the league’s highest-scoring team last season even before they brought in Antawn Jamison and Antoine Walker.

If not for a knee injury to Dirk Nowitzki, the Mavs might have made it to the NBA Finals last season. But that didn’t stop them from pulling off a pair of blockbuster deals without having to split up their core of Nowitzki, Steve Nash and Michael Finley.

“I don’t know when we will make beautiful music, I hope it will be someday, but I don’t know that it will be opening day. There will be an adjustment for everyone on our team,” coach Don Nelson said.

On paper, it’s debatable whether the Lakers or Timberwolves improved the most.

Los Angeles, ousted from the second round of the playoffs in six games by the Spurs, signed free agents Malone and Payton to try to get them their first championship rings and return the title to Los Angeles for the fourth time in five years.

If he wins another championship, Phil Jackson will break a tie with Red Auerbach for most titles as a coach (nine).

“We may struggle early,” said Jackson, whose team started last season 11-19 before winning 39 of its final 52 games. “We’ve got a much tougher start this year than we did last year. I think our opponents are more high-quality opponents.”

The Kings-Lakers rivalry has been the NBA’s best over the past few seasons, and a new twist has been added through Sacramento’s acquisition of center Brad Miller – an All-Star with the Indiana Pacers last season.

It was back in January 2002 that O’Neal threw a roundhouse punch at Miller – then with the Bulls – that fortunately missed its intended target. It led to a three-game suspension for O’Neal and a lifetime of Miller thanking his lucky stars for Shaq’s poor aim.

Miller and O’Neal have faced each other just once since then, but they’ll now hook up four times a year.

The regular season also will include four Spurs-Lakers games, four Mavericks-Lakers games, four Spurs-Mavericks games, four Mavericks-Kings games, four Kings-Spurs games, four Timberwolves-Lakers games, four …

Wait a minute, what about the East?

Well, the region that produced the utterly unwatchable Pistons-Nets conference finals has undergone some changes, too – though they’re nothing compared to the wholesale upgrades made by the powerhouses of the West.

Perhaps the biggest change is the addition of Alonzo Mourning to New Jersey, the East’s representative in the past two NBA Finals.

Though they did not improve their biggest weakness – outside shooting – the Nets did add a seven-time All-Star to a lineup that already includes Jason Kidd, Kenyon Martin and Richard Jefferson.

Among the East’s other strongest teams, the main moves were of a different variety.

Detroit, Indiana and Philadelphia changed their coaches and the Boston Celtics traded away their second-leading scorer.

“Any time you’re trying to repeat at anything, it’s a tall order because everyone is gunning for you,” Nets coach Byron Scott said. “We have a veteran team. Even our young players have been in situations that a lot of other young players haven’t been in. The thing that we have to do is maintain our focus throughout the season. We have to set higher goals.

“Obviously, the way we look at it here this year is that we want to win a championship. The bar has been raised.”

This will be the final season the NBA exists as a 29-team league split into four divisions.

With the Charlotte Bobcats entering the Eastern Conference next year and the New Orleans Hornets moving to the West, the league will be split into six five-team divisions but will continue to have eight playoff teams from each conference.

There also is no guarantee that the league’s marquee team, the Lakers, will stick together with their new cast of characters for more than one year.

Malone and Payton have player options for the 2004-05 season, and Bryant faces the possibility of spending next season and several more behind bars if convicted of sexual assault.

Before his trial, however, so much else will unfold.

Can the Spurs win another title with Rasho Nesterovic, Ron Mercer, Robert Horry and Hedo Turkoglu forming the nucleus of Tim Duncan’s new supporting cast? Can Latrell Sprewell, Sam Cassell, Michael Olowokandi and Mark Madsen help Garnett finally get out of the first round of the playoffs?

Will the early season absence of Chris Webber doom the Kings into falling out of the top four and then having to open the postseason on the road?

Can Nelson harness the power of five potential 20-point scorers and turn them into a cohesive unit?

And what about the East? Can Tracy McGrady lead the NBA in scoring again? Is LeBron James worthy of the hype? Can Scottie Pippen lead the Chicago Bulls back to the playoffs? Are the knees of Vince Carter and Antonio McDyess OK?

“We have a lot of people waiting for our season to begin,” commissioner David Stern said, “including me.”

The answers start coming Tuesday night.