Are the Handicaps Fair? Age and Participation Effects in the Dipsea Race

The Dipsea Race is a longstanding annual trail race that takes place in Marin County, California. A unique feature of the Dipsea is that runners are given head starts based on their age and sex, computed in an attempt to give runners of every age and sex a similar chance of winning the race. However, runners in the “scratch group” (19- to 30-year-old men, who receive no head start) have not won in the past 50 years, and nobody between the ages of 9 and 45 has won for the past two decades. In this article, we investigate whether the head starts are too large, giving younger and older runners an advantage, or whether the gap in the age distribution of winners is due to participation differences. We find that if anything, the head starts are smaller than they would need to be for the median or mean time to be similar across age and sex groups; rather, exceptional young and old runners participate at a higher rate than exceptional runners in the scratch group.