For fans of NCAA basketball, it has been an upset-filled March Madness. But there are no surprises in household viewing patterns among the top markets tracked by Nielsen. More than a quarter of households in the Louisville, KY, market tuned into watch the University of Kentucky defeat Cornell on March 25. The Louisville market is once again the highest-rated DMA for NCAA tournament games, averaging a 16.6 household rating through the first two rounds.  While Louisville is a mid-sized market with no pro sports teams, it dominates NCAA viewership and is at the heart of a "basketball belt," an enthusiastic cluster of markets from Raleigh to Oklahoma City that boast nine of the top 10 DMAs in tournament viewing.

Louisville also has the highest average viewership for the NCAA championship game the past 10 years. Historically, viewership hasn't wavered despite the fact that neither the University of Louisville nor the University of Kentucky have sent teams to the championship game since 1998.

Further analysis shows that Louisville is more than just a college basketball town. When compared to the rest of the U.S., the "Derby City," is roughly three times more likely to watch horse racing's Triple Crown (including the Kentucky Derby, obviously) and is twice as likely to view the Indy 500 and Daytona 500.