A double belly-buster may sound like the name of that drink your roommate made you last Saturday right before you threw up. Andy Bellin, author of “Poker Nation,” would correct you by saying that a double belly-buster is actually a hand in poker.

Andy Bellin was on his way to a master’s degree in astrophysics when he made the mistake of falling in love with poker. It seems a casino near campus attracted more of his time than the books he was supposed to be studying.

Bellin, who spoke at University Book Store Feb. 20, left school (before they could fail him out) and went home to New York. There, he discovered underground poker.

After borrowing money from many people, Bellin fulfilled a goal of his by playing in a large poker game. He played his first game with members of the Genovese crime family. “There are some dangerous people, there are some stupid people,” Bellin said. “Some guy tried to rob one of the joints that I was playing in, and everybody started to laugh at … this guy pointing the gun at them.” His repertoire of fellow players includes a lot of strange characters, too.

Bellin played poker with a Cal Tech dropout named Huck. “He stood on his head for 21 hours and made $100,000,” Bellin said. “This is what these people do to amuse themselves.”

“There are so many strange people because poker players are insulated,” Bellin explained. “They have no contact with the outside world.”

Besides the funny anecdotes, Bellin talked of the finer points of poker.

In addition to speaking about probability, he also discussed ‘”tells.” “Tells are things people do that give away their cards,” Bellin said. “People look at their cards, they have a pair of kings — they sit up straight.” Among the more technical elements of poker are the ups and downs that come with every player.

Bellin’s biggest loss ever on a single hand was $9,400. “The good players get their teeth kicked in and they sit down and they smile,” Bellin said.

Bellin could not recall the most he’s ever won on a single hand. “Last week playing in Hollywood I won $5,200,” Bellin said. He currently lives in Hollywood and plays poker with actors. “I do e-mail David Schwimmer’s checks around all the time,” Bellin said.

Bellin’s next venture is a book on the world of horse racing; he now owns a share of a problematic racehorses. “It [the horse] got too heavy because the stable guy was feeding it too many peppermints,” Bellin explained.

Bellin’s writing has appeared in publications including Esquire, Details, and Maxim. He is also an editor at the Paris Review.