About five years ago, Rubin’s father mentioned that Avi’s younger brother, Yaacov, had been winning money playing poker online. Soon after, Avi suggested to Yaacov that they play sometime. “He kind of laughed at me and started asking a few questions about hands and situations,” Rubin recalls. “He said, ‘You know so little about poker, you don’t realize that you don’t know anything about poker.’” Rubin thought his little brother was just being arrogant, but when Yaacov recommended a poker book called Harrington on Cash Games: Volume I, Rubin read it at a few sittings, highlighting the text, making notes, utterly engrossed. “It was probably the most fascinating experience I’ve ever had, to read that book and understand the science and the math behind poker and to realize that a game I’d considered fun my whole life actually had more depth than I’d ever considered,” he says. After his family and his work, poker became Rubin’s main interest, displacing pocket billiards, his previous obsession. He is a man of strong enthusiasms, serially all in, you might say, and now he bought every poker book he could find and studied them for hours, rereading the best ones. He started seeking out games with better players, learning by losing until he began to win. And he set a goal—to play his way into the World Series of Poker in Las Vegas, the biggest poker tournament in the world, by the time he was 50.