If this were the NFL, the answer might suggest so. In the last six Super Bowls where the #1 defense faced the #1 offense, the defense has prevailed five times, including this past Super Bowl. Granted, that sample size is not large enough to draw any legitimate conclusions, it is still quite interesting and would confirm the ‘defense wins championships’ mantra with some people.
However, this is not the NFL. With the increase in scoring in college hoops over the last six seasons, it may appear that it is not defense that wins, but rather a high powered offense, yet this topic is deserves deeper analysis: it is time to really take a look at the last 15 national champions to see if nearly every coach’s favorite saying is true.
First, looking at each NCAA tournament runner up, there is hardly any difference in each team’s adjusted offensive or defensive efficiency rank (via KenPom). On average since 2002, each runner up ranked 18.07 on offense and 18.87 on defense out of all 351 teams entering the tournament. There are a few numbers that skew this data, however. In Butler’s second miraculous run to the finals in back to back seasons (2010 and 2011), the Bulldogs ranked 34th in offensive and 72nd in defensive efficiency in the country. The year before in 2010, the Bulldogs ranked 48th offensively. Similarly, Michigan’s defense in 2013 ranked 66th, very lopsided in comparison to their 2nd ranked offense; this might suggest it was their relatively poor defense that caused them to lose to Louisville in the finals who possessed the #1 defense entering the tournament.
When looking at the victors, a similar story is told, but only slightly better in each category. The average national champion’s offensive rank over the last 15 years is 13.80, where its defense is 14.93. This offensive rank is skewed by UConn’s 58th rank in 2014, during their second miraculous title run in four years. Both of UConn’s national championship wins were against teams with weaker than average offensive and defensive ratings (2011 Butler at 34th and 72nd and 2014 Kentucky at 19th and 35th.) In both instances, the Huskies’ defense ranked much higher than their opponents. A correlated groups t-test* comparing the champion’s offensive rating to their defensive as well as the same comparison for the runner up were tested, and in both cases I could not conclude that a statistically significant difference existed (p** = .402, p = .906). Likewise, a t-test comparing the champion’s defense to that of the runner up yielded the same result of the inability to conclude a statistical difference in the rankings (p = .292).
*A correlated groups t-test is a statistical test that checks whether there is a statistical difference between the population means of two groups. Also known as super nerdy stuff not very applicable to everyday life.
** The probability of yielded a result as extreme or more extreme than was actually observed, given that there is no difference in the average ranking between the runner up and champion
Alright, enough of these complex numbers; what does this actually mean? Well, despite the champion being ranked slightly higher on average (they did win, doesn’t that mean they’re the better team anyway?) there is no statistical difference between a team’s offense and defense, and none between the defenses of the winner and loser in the championship game. Therefore, I think it is safe to conclude that in college basketball, defense is not what wins championships. In the last 15 seasons, the #1 defense in the country entering the tournament has lost in the championship once of two appearances (2008) when Kansas, with the #1 offense and #3 defense in Division I defeated Memphis (the other appearance was Louisville’s victory over Michigan in 2013). The team with the #1 most efficient offense in the tournament is 3-1 in the championship game since 2002, with its sole loss (Wisconsin) came against Duke in 2015. Besides these weak relationships, there is no conclusive data on whether or not the more defensively minded teams have a greater chance of winning the tournament. It is interesting to see that there is very little difference in average defensive and offensive ratings for both the champion and runner up, suggesting that more balanced teams with both categories inside the top 20 are the most likely to win, rather than having one category be significantly better than the other. Looks like Virginia will not be winning a national championship anytime soon.