7:41 with the extremely secretive world of high stakes underground poker about to get blown wide open with Molly's game. An insider's look at the a-listers who came to play and Molly bloom is naming... See More
7:41 with the extremely secretive world of high stakes underground poker about to get blown wide open with Molly's game. An insider's look at the a-listers who came to play and Molly bloom is naming names like Leo, Toby, Matt, Ben and a-rod. Molly bloom was the voluptuous Hollywood madam of poker and says she lured billionaires and celebrities alike. Faces you know from the red carpet to an underground high-stakes game of no limit Texas hold 'em in swanky five-star hotels in Los Angeles. The first night as the players started walking in, they would hand me their buy-in which was all in cash and it was just a double shock because not only were some of the most famous faces in the world but handing me this stack of $10,000 and I'm standing in the background counting $100,000. Reporter: According to Molly she organized these star-studded games for high-rolling players including celebrities like Leonardo Dicaprio. Leo would walk in with his headphones on and seem a bit detached and for so long it didn't make sense to me and then eventually I realized why that was. Why. Tobey would put Leo in the game in order to attract bigger players. So Leo wasn't into playing the game. He was there as the magnet. Yeah. Reporter: The Tobey she's referring to is actor Tobey Maguire. I used to call him Hannibal lecter because he could talk someone off a good hand. He won a lot. Yeah. How much was he winning. Over the years, millions. What was it like to see all of these high rollers, incredibly successful wealthy men sitting at a table when there was just that money at stake and their ego at stake, as well? It was stressful. Reporter: But stress aside Molly was immediately intoxicated by the mixture of glamour, wealth, secrecy and most of all the cash tips she received from the winners. That first night how much money did you make if tips. Around 3,000. What was your reaction? I got in my car, locked my car and was like screaming. And then the money just kept getting better. It did. Reporter: For Molly bloom perfecting the game meant studying their poker personalities. I'll call the two grand and gamble. Reporter: Matt Damon she says was nothing like the poker addict that gambled everything in the film "Rounders." He was lovely. Modest, down to Earth. A nice, smart guy. Reporter: She says Damon's pal Ben Affleck was a regular whose pen chapter for gambling has made the news. He had the gambling gene. No question. Reporter: She said the a-lister that attracted the most attention was Alex Rodriguez. There's something ha happens to grown men no matter how successful they are when a professional athlete comes into the room, they're reduced to kind of like, you know -- Teenage girls. So a-rod usually won because people would fold to him. By default. He had basic skills but people played very differently when they were in a hand with him. They were kind of gaga. Teenage girls. Yeah. Molly's game goes on sale next week. Back in 2011 Alex Rodriguez's spokesman denied the ball player's involvement. We contacted the other celebrities named by Molly bloom. They all declined to comment but you can see much, much more of my interview with Molly tonight on "20/20" at 10:00 eastern right here on ABC. She has a lot to say. I bet she does.
This transcript has been automatically generated and may not be 100% accurate.