Psychologists and baseball players were among those Americans who formed professional associations in the last quarter of the nineteenth century. Psychologists used laboratory tasks to quantify mental and behavioral processes while sportswriters and baseball organizers measured individual and team performance. The most popular baseball player of the 1920s, George Herman "Babe" Ruth, possessed superior batting skills that were evident in the statistical indices of baseball performance. In 1921, he was brought to the psychological laboratory at Columbia University to perform standard laboratory tasks in an effort to discover the basis for his success in hitting home runs and to suggest the potential of tests for identifying future baseball stars. Baseball's addiction to quantitative indices of performance was thus brought together with a new science devoted to quantitative assessment and a desire to make such assessments useful. The attempt to analyze the basis of Ruth's batting skills is part of the history of applied psychology, sport psychology, and popular interest in the science of psychology.