Calculated Bets describes a gambling system that works. Steven Skiena, a jai-alai enthusiast and computer scientist, documents how he used computer simulations and modeling techniques to predict the outcome of jai-alai matches and increased his initial stake by 544% in one year. Skiena demonstrates how his jai-alai system functions like a stock trading system, and includes examples of how gambling and mathematics interact in program trading systems, how mathematical models are used in political polling, and what the future holds for Internet gambling. With humor and enthusiasm, Skiena explains computer predictions used in business, sports, and politics, and the difference between correlation and causation. An unusual presentation of how mathematical models are designed, built, and validated, Calculated Bets also includes a list of modeling projects with online data sources. Steven Skiena, Associate Professor of Computer Science at SUNY Stony Brook, is the author of The Algorithm Design Manual (Springer-Verlag, 1997) and the EDUCOM award-winning Computational Discrete Mathematics. He is the recipient of the ONR Young Investigator's Award and the Chancellor's Award for Excellence in Teaching at Stony Brook. His research interests include discrete mathematics and its applications, particularly the design of graph, string, and geometric algorithms.