LAS VEGAS - Charles Darwin -- Mr. Survival of the Fittest -- would've loved summer NBA ball, with the unemployed all taking risks they'd never consider under guaranteed contracts.

Tuesday morning it was guard Guillermo Diaz, desperate to keep a loose ball in play. He crashed into a row of folding chairs at UNLV's Cox Pavilion, toppling 20 or more of them.

"Wow!'' new Charlotte Bobcats coach Larry Brown shouted, stifling a chuckle, "looked like a row of dominoes!''

The chuckles were constant, with Brown back home. Not in the desert, but in the gym. Two years removed from his last coaching gig with the New York Knicks, Brown was running practice again.

And thriving.

"I missed it," Brown said. "It's one thing watching other people coach. Most of the places I went [to observe], people asked me to do things. But it's not the same as an opportunity out on the floor. That's special."

He treats it as special. Sixty-seven years young, the guy was as energetic and attentive as any of the 16 kids vying for spots on the summer-league team that starts playing games Saturday.

Think of the cliche football coach, suspended from a tower above practice fields, surveying as if from a throne. Now imagine the other extreme; Brown sprinting to the players, hands flying to illustrate his points.

When rookie point guard D.J. Augustin didn't cut off a pick sharply enough, Brown demonstrated with his own dribble, finishing with a lob pass to rookie center Alexis Ajinca.

If it weren't for the gray hair and horn-rim specs, you'd thought Brown was auditioning, not coaching.

"I don't know how old he is,'' Bobcats forward Jared Dudley observed, "but wow, he's in good shape, the way he was running up and down" the court.

That energy helped set an agenda: He can live with mistakes, but he won't tolerate a lack of conditioning and effort. A baseball fan (Brown uses the term "center fielder'' constantly to remind big men how to guard the basket), Brown would endorse the baseball axiom that if you must make a mistake, make an aggressive mistake.

"I told them all we can't teach effort -- they've got to have their motors running when they get here -- we can only teach execution," Brown said. "When I see a kid cares, even when he's screwing up, that's really important."

Brown and his staff flooded these players -- three veterans, three draft picks, the rest free agents -- with terminology Tuesday.

The jargon -- "basic," "basic-fist," "drag," "swing," "dive" and a late-possession play called "butter" -- required an English-Brown dictionary to keep up.

Brown never expected them to keep up. He inherited this approach from his mentor, North Carolina's Dean Smith: Install a wealth of plays initially, then refine execution over time.

This was the survey portion of Brown on Basketball 101. The higher-level classes will come after he makes some cuts, and ultimately a couple of invitations to fall training camp.

That two-year hiatus from coaching left Brown bouncing around the college and pro game, watching others use gym as classroom. He can't wait to install what he learned.

"Everybody watched us coach because [the NBA] season goes longer and starts earlier," Brown said. "So I never got an opportunity [to watch]. It reinforced a lot of things I believed in, but it also showed there are a lot of different ways to do things."