One of the things that makes the annual NCAA basketball tournament such a hit is its unpredictability.

Just when you figure you’ve got March Madness (and its brackets) down, something comes along.

Now, I’ve been watching this annual two weeks of madness for a long time. Once upon a time, I used to take a week’s vacation to rest up after a busy season of sports coverage.

But the week off always came, coincidentally, during the first week of the NCAA hoops tourney. My wife could only shake her head in disbelief.

Unlike most other collegiate sports, NCAA basketball has managed to create its own viewing niche.

NCAA baseball has tried to emulate that success, but it’s simply too long and drawn out.

You would think college football, with all of its glitter and rankings, would rank higher. But college football is restricted almost entirely to the royalty of the game, the Alabamas, Ohio States, Clemsons, USCs, etc.

College hockey has finally adopted a good playoff format. But the sport remains a regional sport with a limited number of teams.

The major cachet about NCAA basketball is its wide range of interest. Even people who don’t follow — or even like the sport — are invariably entered in office pools.

This year’s tourney contains a number of sub-plots.

In Northwestern, you had a team that was trying to duplicate the success of its neighbors in Chicago, the Cubs.

The Wildcats lack of success over the years (zero NCAA bids) was very similar to the Cubs long drought.

NU even won its opener this year, with the help of super fan Julia Louis-Dreyfus, who has a son on the team.

Dreyfus, one of the stars of the highly successful Jerry Seinfeld sitcom, was the target of more cameras than the game itself.

This isn’t unusual. Most major college teams have high visibility personalities who follow them faithfully. And if UCLA makes it to the Final Four, we’re going to see a number of them.

Or how about Purdue reserve guard Spike Albrecht? Because of the NCAA rule that gives athletes a fifth year of eligibility, the former Michigan standout sub is still out there and could face his former team.

Had Northwestern advanced, we might have had the entire Seinfeld cast in the stands. Just think about that scenario.