AARON BROWN has used numbers to make bets and investigate questions all his life. He was playing poker in tavern backrooms and winning at the horse races while still in middle school. He was one of the top professional poker players in the 1970s and 80s, and is also successful in sports betting, advantage casino play and prediction market trading. Brown moved to Wall Street in the early 1980s to use the same skills as a trader, portfolio manager, head of mortgage securities and risk manager for top global financial institutions. He is a former Chief Risk Officer at AQR and winner of the 2011 GARP Risk Manager of the Year award. Brown holds degrees in applied mathematics from Harvard and finance and statistics from the University of Chicago. He has taught mathematics and finance at New York University, Columbia, and other institutions. Brown publishes frequently in academic and professional literature, and has served as a statistician on hundreds of scientific studies. He has been a data and methodology reviewer for major scientific journals. His previous books are The Poker Face of Wall Street, Red-Blooded Risk, A World of Chance, and Financial Risk Management for Dummies.