JEFF SEIBEL, a 52-year-old computer programmer who lives in Albany, says he got into playing Texas HoldEm poker on the Internet after he threw out his back playing table tennis a year and a half ago. Up until that point, he says, he hadn't played poker since high school.

Now he regularly plays online, betting real money to enter tournaments or play straight up games.

Seibel, who works from home and plays mostly limit Texas HoldEm at various Internet sites, is a member of the new breed of poker players who choose to play poker for money online rather than at land-based casinos.

This year, more than $1 billion is expected to be wagered at Internet Texas HoldEm poker sites, according to PokerPulse.com, which tracks activity at 21 of the largest poker sites.

Seibel plays Texas HoldEm at various sites -- including PartyPoker.com. He likes that site because a lot of the players are loose, he says, which means he can make money. In the middle of providing that explanation, he pauses.

"Sorry about that, can you hold on?" he asks, saying that he is in the midst of playing poker online even as he's being interviewed over the phone. "I'm in the middle of a good hand. King Queen suited. I got a King on the flop."

About twenty seconds later, he returns to the phone conversation to report that he won $32.

The allure of winning money by playing an age-old game on the Internet has pushed online poker, which experts say is legal to play in California, to the forefront of the gaming industry.

In January 2003, $11.1 million was wagered at the major Internet sites, according to PokerPulse.com. In October 2004, the monthly total reached $136.1 million, the firm says.

For some, online poker is a way to make money. For others, like Seibel, making money is good -- but it's not the reason they play.

"I make a lot more money when I'm writing software. I play mostly for enjoyment and fun," Seibel says.

The online Texas HoldEm poker craze is largely credited to the explosive growth of televised poker. And everyone familiar with the industry cites the same pivotal event.

In May 2003, an unknown 27-year-old Internet poker player named Chris Moneymaker (yes, his real name) won the Kentucky Derby of poker -- the annual World Series of Poker held at Binion's Horseshoe Hotel & Casino in Las Vegas. The prize for beating the swarm of professionals and other amateurs was $2.5 million. The real kicker, though, was that Moneymaker qualified for a seat at the tournament (which normally costs $10,000) by winning an online series of satellite tournaments, which cost him only $40 total to enter. Moneymaker also said he had never played in a live poker tournament before the World Series. He had only played Texas HoldEm online.

"We've seen quite a few unknowns go to final tables of major (land-based) events and do extremely well against the pros. And where have all these people honed their skills? Online," says Vikrant Bhargava, general manager of PartyPoker.com, which is owned by iGlobalMedia, based in Gibraltar.

Bhargava says his firm's site -- which PokerPulse.com calls the largest online destination -- has 60,000 players at tables in peak traffic, suggesting a couple hundred thousand visitors per day. The bulk of the customers come from the U.S.

Most of the players are male, Bhargava says. Patrick Selin, CEO of competitor PokerRoom.com, owned by Sweden-based Ongame, confirms this demographic trend.

About 85 percent of players at PokerRoom.com are male and the average age is 28, Selin says.

While almost all online Texas HoldEm poker sites let players play around with play money, the operators don't earn any money from them. So efforts are made by the sites to encourage players to load up accounts and play with real money.

During Halloween weekend, PokerRoom only allowed players who had money in their accounts to play. To entice new customers, special bonuses were offered for deposits.

The draw for many players continues to be the tournaments and the hope of becoming the next Chris Moneymaker.

"With tournaments, it's that dream ... meeting the big poker stars, being able to travel somewhere and hopefully winning a million dollars or whatever (the prize) is," Selin says.

But while Texas HoldEm poker is growing at a phenomenal rate, Selin admits the gold rush could diminish soon. He says the amount wagered online skyrocketed by more than 600 percent in 2003, but this year's growth rate is expected to be 150 percent. He expects next year's growth rate will be 100 percent -- meaning total wagering will double.