How Often Are NCAA Tournament Games Decided By 3 Points Or Less?

There’s a lot to consider when betting college basketball odds during NCAA Tournament season.

Most bettors know that tournament games are often competitive. But just how competitive? 

Put another way – how valuable is that 3.5-point spread in a given March Madness game?

I dug into all the numbers to find an answer.

How Often Are NCAA Tournament Games Decided By Three Points Or Less?

From 2021-24, there were 38 NCAA men’s basketball tournament games that ended with margins of three points or less. That means they finished as one-possession games. 

That’s about 14% of all tournament games, or roughly one in seven.

Keep that in mind next time you’re considering a small underdog.

NCAA Tournament Game Margins

Point spreads get a little more interesting when they expand beyond the value of a single-game possession.

On average, there have been about four games per tournament that end with four-point margins, meaning a move in the point spread market from +3.5 to +4.5 can actually provide quite a bit of value for underdog bettors.

But +6.5 appears to be the real leverage point, with another seven games per tournament (on average) falling on either a five-point margin or a six-point margin. 

While 5.5 remains one of several key numbers in sports betting during the college basketball regular season, it appears 6.5 is a stronger number for NCAA Tournament betting specifically. That’s according to the results from 2021-24, anyway.

Summing all those advantages, an NCAA Tournament bet on a dog of +6.5 would blindly cover between one-fourth and one-third of all March Madness results in recent years, depending slightly on annual variance. 

Bettors could improve those hit rates even further by using some discretion in the underdogs they research and bet.