March Madness is heading to the Sweet 16 without a handful of top teams. Two No. 1 seeds, Kansas and Purdue, No. 2 seed Arizona and No. 4 seed Virginia are all gone — and gone with them are millions of busted brackets.

Tough sledding for the bluebloods, too: Besides Kansas, Kentucky and Duke are heading home. But UCLA and Indiana were still alive!

Here is what to know with the regional semifinals up next at the NCAA Tournament:

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 appeared 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 if you like underdogs!

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 or Creighton. Or … Princeton, which 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 Xavier or the winner of a tasty 4-5 matchup between Indiana and Miami.

WEST REGION: Kansas, the defending national champion that was without coach Bill Self in the tournament following a heart procedure, blew an 8-point halftime lead and lost to 8-seed Arkansas. Like the East, the West is now open for the likes of No. 2 seed UCLA, No. 3 Gonzaga and either UConn or Saint Mary’s.

SHINING MOMENTS

The unforgettable plays are piling up.

Princeton used a late run to earn its first NCAA Tournament win in 25 years by ousting No. 2 seed Arizona and then answered any skeptics by rolling Missouri to lock in its regional semifinal spot. Furman celebrated its first tourney appearance since 1980 with a win over No. 4 seed Virginia on a deep 3-pointer by JP Pegues with 2.4 seconds left.

Then came 16-seed Fairleigh Dickinson’s win over Purdue as the 22 1/2-point underdog stifled 7-4 center Zach Edey to advance and join UMBC in the record books.

All that happened before the Razorbacks and shirtless coach Eric Musselman celebrated their win over top-seeded Kansas.

GAMES TO WATCH

No. 5 seed San Diego State (29-6) vs. No. 1 seed Alabama (31-5), Friday

The Aztecs are heading to the Sweet 16 for the first time since 2004 and have won 11 of their last 13. Balanced scoring carried them to a second-round victory against Furman and they’ll need more of the same against the Crimson Tide, who handily dispatched Maryland in the second round. All-America freshman Brandon Miller, who is nursing an injury, had 19 after going scoreless in the first round.

No. 3 seed Xavier (27-9) vs. No. 2 seed Texas (28-8), Friday

The Musketeers are heading to the Sweet 16 for the first time since 2017 and will face a Longhorns team that hasn’t been there in 15 years. Xavier put on a clinic on unselfishness in the first half of its 84-73 victory against Pittsburgh, totaling 17 assists on 19 made field goals. The Longhorns made just one 3-pointer in 13 tries in their 71-66 victory against Penn State, but Dylan Disu had season-high 28-point performance.

GO DEEPER

Gun violence has cost lives and disrupted college sports all season, touching some of the top programs in college basketball, including Alabama. Coaches have been thrust into uncertain and unwelcome roles in trying to navigate the topic — as well as the fallout from the Supreme Court decision to overturn Roe vs. Wade.

On a lighter note, if you feel you know March Madness pretty well, try this 25-question trivia quiz put together by AP.

PLAYERS TO WATCH

The NCAA Tournament is filled with great players and the AP All-America team is a good place to get familiar with the names. It’s also an event where guys you’ve never heard of can take a star turn. Guard play is always going to be important (see: Baylor, 2021 title winner) and there are some NBA prospects in the mix.

Bet on this, too: Some player — maybe more than one — will have a chance to join the mustachioed Doug Edert (remember Saint Peters’ inspiring run last year?) and find a way to cash in on their celebrity.

HOW TO WATCH

Every game of the men’s tournament will be aired — here is a schedule — either on CBS, TBS, TNT or TruTV and their digital platforms. CBS, which also has a handy schedule that includes announcing teams, will handle the Final Four and national title game this year.

The NCAA is streaming games via its March Madness Live option and CBS games are being streamed on Paramount+. Fans of longtime play-by-play announcer Jim Nantz should soak up every moment: It’s his final NCAA Tournament.

BETTING GUIDE

Who’s going to win the national championship? The betting favorites Sunday to reach the Final Four are (in order) Houston, Alabama, UCLA, Texas, UConn and Gonzaga, according to FanDuel Sportsbook.

MARCH MADNESS CALENDAR

Selection Sunday set the bracket matchup s for the First Four and first- and second-round games that stretch from Florida to California. Sweet 16 weekend will see games in New York City (East Region), Las Vegas (West), Kansas City, Missouri (Midwest), and Louisville, Kentucky (South).

Where is the Final Four? In Houston, on April 1, with the championship game on April 3. Basketball aficionados, take note: The women’s NCAA Tournament will hold its Final Four in Dallas, a four-hour drive up the road from Houston.

Can’t get enough March Madness? Well, there is talk about expanding the tournament despite a host of challenges. Enjoy the 68-team version for now!

By The Associated Press