Barry Greenstein, nicknamed the "Robin Hood of Poker" for donating millions of dollars of his tournament winnings in support of his favorite causes, is not only respected for his philanthropy, but also his undeniable poker talent.

He owns two World Poker Tour titles and three World Series of Poker bracelets from the 2004 $5,000 no-limit deuce-to-seven draw, the 2005 $1,500 pot-limit Omaha, and the 2008 $1,500 razz events. Also in 2008, Greenstein made the final table of the $50,000 H.O.R.S.E. event, making him the only player to have cashed in all three years the event has taken place.

Born in Chicago, Illinois, in 1955, Greenstein has been playing cards since the age of 12. He began by playing gin rummy and hearts, and eventually poker. He managed to win enough to pay for college by playing cards with local businessmen. He graduated, and then spent a decade earning a graduate degree in mathematics. Finding that poker was much more lucrative than a job in his profession, he decided to dedicate himself to the game. He now competes in the highest cash games and richest tournaments in the world.

Greenstein represents PokerStars as a member of its team. In addition to being a successful player and philanthropist, he has also written a book, Ace on the River. He gives anyone who knocks him out of a tournament a signed copy.