Kentucky by the Numbers

This is the seventh time in the past 28 years that the NCAA Men’s Basketball championship game has matched a number one and a number two seed.  In fact, the one-two matchup is the most common championship game since the 64 team format began in 1985.  The first time a number one seed faced a number two seed in the final game second seeded Louisville defeated Duke in 1986.  (Louisville had a higher Ratings Percentage Index).  Since then the number one seed has won five straight championship games against number two seeds and six of eight games against teams seeded third or lower.

Number one and number two seeds have met 54 times in the past 28 years of March Madness.  48 of these match-ups were in the regional finals and the national semi-final games.   In these 48 games number one seeds won exactly half of the games.  So far this year, a number one seed has not defeated a number two seed, but second seeded Ohio State and Kansas defeated top seeded Syracuse and North Carolina in the regional finals.    

The number one seeds that advance to the championship game, however, appear to be the strongest teams playing the best basketball in March.  Since Georgetown’s loss to Villanova and Duke’s loss to Louisville, a number one seed has won 85% of championship games against lower seeded opponents.  Look for Kentucky to continue this trend and defeat Kansas by 6 to 7 points, the average margin of victory in championship games between one and two seeds.

Upsets and March Madness

The last decade of men’s college basketball has seen increased parity between the power conferences and mid-major conferences.  Friday’s NCAA Tournament results epitomize this shift.  Prior to Friday number 2 seeds won 96.4% of their games against number 15 seeds over the past 27 years.  Both number 15 seeds defeated their second seeded opponents when Lehigh upset Duke and Norfolk State upset Missouri on Friday.  These upsets would have been even more surprising had they occurred in the 1980’s and 1990’s when the gap between college basketballs’ haves and have-nots was much wider.  In the past decade the NCAA’s pod system has given more favorable site assignments to highly seeded teams and limited the number of upsets mitigating the impact of increased parity.

 Today the best players often stay for a single year of college basketball before turning pro.  Consequently the top seeds are usually less experienced and start more freshman than many of the lower seeded teams.  This was not true in the early years of the 64 team format, when teams from traditional powers such as Kansas, Kentucky, North Carolina, and Duke had more talented players and more experienced teams.

March Madness upsets are now more likely to occur because the gap between top and lower seeded teams is the smallest since the 64 team format was introduced in 1985.  One way to measure the gap between stronger and weaker teams is through the Ratings Percentage Index, or RPI.  Teams with a higher RPI have defeated better teams that played stronger schedules during the regular season. 

The RPI methodology has changed over the years, so I compare relative RPI differentials in first round tournament games.  The smallest RPI differentials are in games between teams seeded 8 and 9, and the next smallest differentials are in games between teams seeded 7 and 10.  I normalize the double difference in RPI in opening games involving 7-10 and 8-9 seeds as a baseline for measuring other RPI differentials.

During the 1980s and 1990s the relative RPI differential for the average number 5 seed was 6.6 times the baseline RPI differential.  Over the past 6 tournaments the average number 5seed faced a relative RPI differential that was only 1.5 times the baseline differential.  The same is true for other highly seeded teams.  During the 1980s and 1990s the RPI differential for the average 2seed was 24.4 times the baseline RPI differential, and has dropped to only 8.3 times the baseline differential in the past 6 tournaments.

This means that today’s number 12 seeds are similar in strength to number 10 seeds in the 1980s and 1990s, and number 15 seeds are similar to previous number 12 seeds.  As I mentioned in an earlier post, my research with Todd McFall indicates that the NCAA’s pod system has mitigated the effects of increased parity by giving more favorable site assignments to the top four seeds in each region.  Despite what we observed Friday night, more favorable site assignments for the top 4 seeds in each region has reduced the number of upsets during the first weekend of March Madness.

In March Madness There’s No Place Like Home

The NCAA Men’s Basketball Tournament is reality entertainment at its best.  The NCAA Selection Committee seeds the tournament to increase the chance that stronger teams advance further.  A tournament structure that increases the likelihood that the best teams play in the Final Four increases television ratings and causes networks to bid more for the rights to March Madness.

The NCAA began using the pod system in 2002 to assign teams to first round sites.  The pod system means that teams from different regions can play early round games in the same city in order to reduce travel distances and costs.  In a study with Todd McFall, of Wake Forest University, we found that the pod system favors the top 16 teams in the country.  The new rules have reduced travel distances for teams seeded two through four in each region.  Top seeded teams had shorter travel distances to first round sites even before the pod system and teams seeded five through sixteen have not seen a decline in travel distances since 2002.

A good example of the impact of the pod system is Duke’s game tonight against Lehigh.  Both North Carolina, the number one seed in the Midwest, and Duke, the number two seed in the South, will play tonight in Greensboro.  Before the pod system, Duke would have likely travelled to either Nashville or Louisville to play South regional games.  Greensboro is just 54 miles from Durham, giving the Blue Devils a clear advantage over a team from Bethlehem, Pennsylvania.

Playing games closer to campus improves a team’s performance.  Our study of over 1700 tournament games found that playing in a team’s home state was worth 1.3 points, and each 100 miles further one’s opponent must travel is worth and additional .14 points.  Combining these two effects, we expect Duke’s margin of victory over Lehigh to be 1.92 points more than if they played at a truly neutral site.  This advantage is comparable to the difference between receiving a two-seed rather than a three-seed in the tournament.

The NCAA gives more favorable seeds to basketball teams with better strength of schedules and higher RPIs.  The NCAA has extended this to giving more favorable first round site assignments to the top 16 teams in the country.  All else equal, this means we are more likely to see fewer upsets of teams ranked in the top four in each region, early in the tournament.  Although this lowers the chance of Cinderella teams advancing to the Elite Eight and Final Four, it will probably produce more competitive games between higher ranked teams late in the tournament.