There is a need for fair measures of country sport performance that include athletes who do not win medals.
Purpose: To develop a measure of country performance based on athlete ranks in the sport of swimming.
Methods: Annual top-150 ranks in Olympic pool-swimming events were downloaded for 1990 through 2011. For each athlete of a given rank, a score representing the athlete's performance potential was estimated as the proportion of athletes of that rank who ever achieved top rank. A country's scores were calculated by summing its athletes' scores over all 32 events. Reliability and convergent validity were assessed via year-to-year correlations and correlations with medal counts at major competitions. The method was also applied to ranks at the 2012 Olympics to evaluate countries' swimming performance.
Results: The performance score of an athlete of a given rank was closely approximated by 1/rank. This simpler score has 1 practical interpretation: An athlete ranked 7th (for example) has a chance of 1/7 of ever achieving top rank; for purposes of evaluating country performance, 7 such athletes are equivalent to 1 athlete of the top rank. Country scores obtained by summing 1/rank of the country's athletes had high reliability and validity. This approach produced scores for 168 countries at the Olympics, whereas only 17 countries won medals.
Conclusions: The authors used the sport of swimming to develop a fair and inclusive measure representing a country's performance potential. This measure should be suitable for assessing countries in any sports with world rankings or with athletes at major competitions.