Evaluating Regional Balance in the NCAA Men’s Basketball Tournament using the Tournament Selection Ratio

The placement of teams, or players, into a tournament’s brackets can have a significant impact on who will emerge as the champion. At Wimbledon, 32 players are seeded among the 128 singles entrants in that particular tennis tournament. UEFA coefficients are used to select those European soccer clubs that will compete for the Champions League and Europa League titles in the following season. Teams that survive qualifying are seeded into groups for the finals of World Cup competition in soccer, basketball and ice hockey. An important question to answer is whether or not the criteria used to determine such seeds will create an equitable tournament bracket. The Tournament Selection Ratio (TSR) was designed specifically to quantitatively address this question with regards to the annual NCAA men’s basketball tournament, where 64 teams are selected from over 340 teams located across the entire United States. The TSR metric will be used to evaluate: if the four regions (16 seeded teams in each) in recent NCAA Men’s basketball tournament have been evenly balanced; if the appointed selection committee, who creates the tournament bracket, has invited the best teams to compete in this sport’s culminating event; and if those invited teams have been assigned the most accurate seeds. The results of current NCAA practices and procedures, as applied by the selection committee for this tournament, will also be compared against previous invitational guidelines.