Who's hot is Louisville, who's not is North Carolina. What's in is Auburn, what's out is Nevada-Las Vegas. What's fashionable is Auburn Coach Sonny Smith, what's timeless is North Carolina Coach Dean Smith.

Welcome to the NCAA West regional, the people's choice awards, where trends may tell all when play opens Thursday at the Summit. If you choose momentum, go with seventh-ranked Louisville (28-7); if you favor breeding, pick No. 8 Carolina (28-5) when these two teams meet at 9:08 p.m. If you like a comer, take No. 11 UNLV (33-4); if you enjoy a secret, take unranked Auburn (21-10) when they meet at 6:37 p.m.

"It's down to that time of year when physically, anyone can win it," Louisville Coach Denny Crum said.

Nevertheless, you have to start with the two perennials, North Carolina and Louisville, who meet in a game that many think will yield the eventual regional champion.

Louisville is the late starter that has won its last 13 straight with a young team led by freshman center Pervis Ellison. North Carolina is the veteran team led by senior center Brad Daugherty that won 21 straight to start the season and seemed so unassailable until a few weeks ago.

But all of a sudden conventional wisdom has it that the Tar Heels can't run or jump. Hobbled by late-season injuries, they lost four of their last five. Steve Hale is recovering from a partially collapsed lung after missing two weeks, Joe Wolf sprained his ankle two weeks ago, and reserve 7-foot center Warren Martin is out of his precautionary cast for a sprained foot.

"All of the injuries may not be healed yet," Daugherty said.

North Carolina may be a little hungrier than it was during the regular season, when it was frequently ranked No. 1. The Tar Heels are tired of hearing about their slump, and they were impressively aggressive in their first two tournament games, defeating Utah, 84-72, and Alabama-Birmingham, 77-59. In addition, although they have made the round of 16 six straight times, they have not gotten to the Final Four since 1982, when they won the national championship.

"I don't think who has won how many games, who is on the streaks, is going to have anything to do with it," Daugherty said. "It's going to come down to who does the little things well."

Starting with his matchup against Ellison. The Tar Heels' 7-foot all-America, who leads the nation in shooting percentage (64.7) and has averaged 20.2 points per game, would seem to have the edge over the 6-9 Louisville freshman. But Ellison is among the most complete first-year players in the country, averaging a steady 12.7 points and 7.9 rebounds.

"Obviously a lot depends on how well Pervis can contain Daugherty," Crum said. "But we aren't going to beat North Carolina by doing the job on one guy."

Ellison probably won't be able to handle Daugherty by his lonesome. He will need help, and he can get it from a Cardinals lineup with something of a size advantage to offset the seven-footer. It is pronounced in the back court, with Milt Wagner (14.7 ppg) at 6-5 and point guard Jeff Hall (10.2) at 6-4. If the Cardinals can avoid the dangerous North Carolina trap in the back court, they may give 6-2 Jeff Lebo and 6-3 point guard Kenny Smith (12.0 ppg) problems.

Auburn's meeting with UNLV will present another contrast, and some similarities. Although perhaps neither was expected to get this far, both have surprised opponents with their sheer bulk and affinity for relentless running offenses.

The Tigers are led by 6-8, 215-pound forward Chuck Person, who was overlooked on all the all-America teams despite averaging 20.4 points and 7.9 rebounds and is making this tournament a vendetta. He is being compared to St. John's Walter Berry and Maryland's Len Bias and is essentially the crux of Auburn's offense.

"We don't have anyone to guard him in our starting lineup," UNLV Coach Jerry Tarkanian said flatly.

The Rebels instead will look to reserve forward Eldridge Hudson, their best defensive player and their most physical at 6-7, 215 pounds.

Auburn's main defensive task will be to stop an array of impressive perimeter scorers, led by Anthony Jones, the 6-7 transfer from Georgetown and former Dunbar High School (Washington, D.C.) star, who has averaged 18.1 points.

It all probably adds up to an offensive draw. Which makes it a foot race. "We'll run," said Sonny Smith. "The only time we won't run is when we don't have the ball. So it will come down to whoever gets the ball."