But the man who created a pop-culture immortal as the craven, self-absorbed George Costanza on "Seinfeld" is making his long overdue AyCee premiere not as himself, but as a caricature of a self-help guru in "Jason Alexander As Donny Clay." The one-man comedy presentation comes to Harrah's Resort Atlantic City Saturday.

As Donny Clay, the 50-year-old Alexander skewers the likes of Tony Robbins, Deepak Chopra and Dr. Phil (McGraw), all of whom have made millions telling other people how to stop being losers and make successes of themselves. The concept, Alexander offered during a recent long-distance chat, had its roots in a failed sitcom.

In 2001, he explained, he starred in "Bob Patterson," which was created by Brad Hall, the husband of his "Seinfeld" co-star Julia Louis-Dreyfus. The series, which also featured Connie Sellecca and her new-age musician hubby, John Tesh, was about a motivational speaker who, though ostensibly a very together guy others should heed, was, at his core, a self-doubting lump of insecurities with a miserable history of failed relationships.

"Bob Patterson" was killed by ABC after only a handful of episodes. But the premise that such individuals were ripe for satire never left Alexander.

"I said to my writing partner [former WYSP-FM talk-show host Peter Tilden], 'Maybe we can build something from this,' " he recalled, adding the show was initially conjured for private corporate engagements. "The corporate dates became so successful, my agent said, 'Can you do this for public audiences?' "

Alexander admitted that making fun of motivational speakers is a theatrical version of shooting fish in a barrel. As far as he's concerned, they are asking for it.

"The people who are best-known for this are complete doofuses," he said. "They are really odd folk. The notion you can go out and tell people how to live their lives is a very [vain] notion. But it is a very rich turf. It bumps into a lot of good subjects, like body issues, sex and money."

The irony, Alexander continued, is that while he clearly is satirizing the whole self-help milieu, audience members keep responding in a surprising way. "It's totally lampooning it," he said, "but the amazing thing is people say to me, 'I learned something.' "

The "Donny Clay" Alexander is bringing to Harrah's is somewhat different from the one corporate audiences have enjoyed.

"Some of the music died over the summer," he said. "It wasn't working with the comedy. So we've taken the non-comedic music out just to see how it plays."

Alexander's Atlantic City stop comes in the middle of the five-episode "Seinfeld"-reunion story arc on the HBO series "Curb Your Enthusiasm," which was created by and stars "Seinfeld" co-creator Larry David.

On "Curb," David, playing an exaggerated version of himself, believes he can mend his busted marriage to his actress-wife (Cheryl Hines) by offering her the role of George's ex-wife in the fictional reunion show.

According to Alexander, David's idea of doing a phony reunion was the only way the four principals - Seinfeld, Alexander, Louis-Dreyfus and Michael Richards - would have agreed to regenerate their "Seinfeld" characters.

For years, he noted, attempts have been made at a serious reunion, "but nobody could come up with a way to do it. There's been no story that is strong enough. This is a non-'Seinfeld' 'Seinfeld' reunion. You get to see [how the characters evolved], but it's not a 'Seinfeld' reunion."

The "Seinfeld" constituency has embraced the faux reunion just the same: The first of the five episodes, which aired Oct. 4, gave "Curb Your Enthusiasm" its largest ratings in five years.

Alexander refused to divulge how it all plays out - not because he was sworn to secrecy, but because he insisted he simply doesn't know.

"The truth is," he said, "there's not much that I know that you don't know, because it's all improvised, so I don't know what's in and what's out."

"Curb Your Enthusiasm" isn't Alexander's only cable-TV vehicle. For a number of years, he has been a regular presence on televised poker programs, first as a contestant on Bravo's "Celebrity Poker Challenge" and, more recently, as a legitimate player on the World Series of Poker telecasts on ESPN.

"I've been playing poker since I was in high school," he said. "But it wasn't until the wave of celebrity television shows happened that I started getting serious.

"I sat down for lessons with [poker superstar] Phil Hellmuth. That started me on my journey of discovery. In the last 10 years, I've become a much more serious student of the game."

So how good is he these days?

"The pros have been kind to me," he said, "but I rate myself a 'B-minus' player."

Does his passion for no-limit Texas hold'em mean Alexander will hit the felt while he's at Harrah's?

"We get there in the late afternoon for sound check, and we have to leave early Sunday," he said. "But I'm up for an all-nighter."

Harrah's Resort Atlantic City, 777 Harrah's Blvd., 9 p.m. Saturday, $60, $50 and $40, 800-736-1420, www.ticketmaster.com.