No top seed has ever lost in the first round since the field expanded to 64. If it is ever to happen, this could be the year.

It’s been that type of season in college basketball. Expect the unexpected.

Remember, everyone (except for me) handed North Carolina the national title before the first ball was tossed up back in November (disclaimer: I actually picked Michigan State to win it all).

The mighty Tar Heels had everyone back, with National Player of the Year winner Tyler Hansbrough and three other guys (Ty Lawson, Wayne Ellington and Danny Green) who all returned after testing the NBA waters.

But North Carolina showed its mortality for the first time against the locals – a Boston College team that was considered an NIT club prior to the start of the season. That’s when everyone else started to believe they had a shot.

Then the Tar Heels lost their only above-average defensive player, Marcus Ginyard, for the rest of the season and a couple more losses to Maryland and Wake Forest showed they had a legitimate chink in their armor.

Wake Forest had a brief stay at the top, but it didn’t last long. Ditto for Duke. UConn and Pittsburgh both tested life at numero uno, but the truth through it all is that there just isn’t a No. 1 team in the country.

This one is up for grabs.

“There’s no doubt it’s wide open,” Pittsburgh coach Jamie Dixon said.

Last season, there were four clear-cut teams going into the season: Kansas, Memphis, North Carolina and UCLA. That same quartet, which all earned No. 1 seeds in the NCAA tournament, advanced to the Final Four in San Antonio – where Kansas wound up knocking off Memphis in one of the more memorable championship games in history.

This is truly the year of Parity – or Mediocrity if you want me to be more truthful.

“If we play well, we can beat anyone,” UCLA coach Ben Howland told me last week. “And if we don’t, we can lose to anyone.”

Howland saw that first-hand on Friday night when his Bruins, who have gone to three consecutive Final Fours, were upset by a USC team that has underachieved all season and appeared to be heading for an NIT appearance.

The disparity between the so-called elite teams and the rest of the field that’ll be unveiled on Sunday night is minimal.

Want proof?

Remember that BC team that beat the once-mighty Tar Heels in Chapel Hill?  It lost days later to Harvard on its own home court.

That Pittsburgh club that everyone fell in love with towards the middle of the season? Well, the Panthers lost at the end of the season at Providence – a likely NIT club – and also couldn’t get past West Virginia (the seventh-best team in the Big East) the other day in the Big East tournament quarterfinals.

The two top teams in the Big 12, Oklahoma and Kansas, were knocked out in their first games of the conference tournament.

And to think, if anything can happen in the regular-season, how insane will this year’s Big Dance be? Maybe there will be even more lunacy than usual.

For one thing, seeding will be fairly irrelevant. The No. 1 seeds – North Carolina, Pittsburgh, Louisville and UConn – are a step above everyone else.

But beyond that, it’s not as if anyone is scared to play, well, anyone. Throw the rest of the teams in a hat because there just isn’t much of a difference. When you fill out your brackets, favorite colors, cities and whatever else may work this season. It’s just that unpredictable.

What is clear is that a new Cinderella story will have to emerge – since Davidson’s Stephen Curry, the darling of March a year ago, is almost certainly headed to the NIT instead of the four-letter tournament.

Don’t worry, though. Even though the number of mid-major teams who will earn at-large berths will likely be down this year, someone else will emerge.

Remember: there’s a reason why it’s called March Madness.