Book excerpt: A practical guide to outguessing everything, from multiple-choice tests to the office football pool to the stock market. People are predictable even when they try not to be. William Poundstone demonstrates how to turn this fact to personal advantage in scores of everyday situations, from playing the lottery to buying a home. Rock Breaks Scissors is mind-reading for real life. Will the next tennis serve go right or left? Will the market go up or down? Most people are poor at that kind of predicting. We are hard-wired to make bum bets on "trends" and "winning streaks" that are illusions. Yet ultimately we're all in the business of anticipating the actions of others. Poundstone reveals how to overcome the errors and improve the accuracy of your own outguessing. Rock Breaks Scissors is a hands-on guide to turning life's odds in your favor.