Prior to 1949, all poker games were cash games; a player could cash out his chips and leave at any time. Pearson originated the idea of a freezeout tournament and shared his idea with fellow gambler "Nick the Greek" Dandolos in the early 1950s. Dandalos later brought the idea to legendary casino owner Benny Binion. After further urging by Pearson, Amarillo Slim, and Doyle Brunson, all of whom felt that such a tournament would create great side (cash) game action, Binion founded the World Series of Poker in 1970. Pearson participated in the first World Series of Poker that year along with Amarillo Slim, Doyle Brunson, Sailor Roberts, Crandell Addington, and Carl Cannon.