Sangamon State University. An earlier version of this paper was presented December 20, 1976 at the Third Conference on Gambling, Las Vegas, Nevada. I am slightly embarrassed at the extent to which I am indebted to others for help of various kinds. Ron Sutherland suggested the framework for this study and provided helpful comments on various drafts. Nancy Jacob and Mark Rubinstein also made several recommendations. H. Fabro, J. Jung, N. Ostroot and J. Rogers gave many tireless hours collecting data. Also, I received the cooperation of the Illinois Racing Board and the Daily Racing Form's statistical editor Don Anderson. But my list would be totally inadequate without expressing my gratitude to J. Miller's T.A. seminar for requiring me to make a “contract” to complete this study.