By The Associated Press

March Madness has begun and top teams are already heading home. By Saturday night, two No. 1 seeds, Kansas and Purdue, No. 2 seed Arizona and No. 4 seed Virginia were all gone — and gone with them were millions of busted brackets.

Here is what to know with Sweet 16 bids on the line at the NCAA Tournament, including the favorites and underdogs as well as key games:

TOP SEEDS

The top four seeds in the tournament were given to Alabama, Houston, Kansas and Purdue. Each had its share of headaches to set up what is already proving to be a chaotic tournament. The Boilermakers were the first to fall, ousted in a first-round stunner, and the Jayhawks followed the very next day.

EAST REGION: The Boilermakers got a No. 1 seed for the fourth time, but Purdue was dumped by Fairleigh Dickinson in a near-historic upset. The region appears to be wide open for the likes of No. 2 seed Marquette, Kansas State, Tennessee, Michigan State and more. No. 5 seed Duke was ousted by the Volunteers. FDU or FAU will advance to the Sweet 16 in the bracket’s biggest underdog matchup.

SOUTH REGION: Alabama, led by coach Nate Oats in a challenging season, is a No. 1 seed for the first time behind SEC player of the year Brandon Miller, who has armed security on hand after being the subject of threats. The Crimson Tide opened the tourney with an easy win. Potential hurdles could include Baylor and Creighton. Princeton is heading to the Sweet 16 out of the South.

MIDWEST REGION: Houston got a top seed and won its opener before a rugged victory over Auburn even with All-American Marcus Sasser hobbled by a groin injury. Potential hurdles could include No. 2 seed Texas, No. 3 seed …read more

Source:: The Denver Post