In its return to complete, boisterous form, the first weekend of the NCAA tournament delivered a Sweet 16 with both the expected and the stunning.

On one hand, Duke, North Carolina, UCLA and Kansas are some of the most blue-blooded programs in college basketball. On the other, Iowa State and Miami will play Friday in Chicago, a matchup that ensures at least one double-digit seed will reach the Elite Eight. And of course there are the small but mighty Peacocks of Saint Peter’s. Here is what to know:

SAINT PETER’S IS even more amazing than its No. 15 seed suggests. On Feb. 20, the Peacocks lost by 14 at Siena, which dropped them to 10-6 in the Metro Atlantic Athletic Conference, a league that Rick Pitino’s Iona was heavily favored to win. The NCAA tournament seemed like a distant hope. The Sweet 16 seemed like an absurd fantasy.

They have not lost since, and here they are, the most improbable Sweet 16 program of all time. Florida Gulf Coast and Oral Roberts each crashed the second weekend as a No. 15 seed, but neither of them play in a home arena like the Yanitelli Center, which seats 3,200 and opened in 1975 after being built for $6 million. The Kentucky team the Peacocks beat is a different animal than the Georgetown and Ohio State squads those other No. 15 seeds toppled in the opening round. Saint Peter’s claims 2,134 undergraduate students on a quiet campus in Jersey City that could be mistaken for a large high school.

The architect of this miracle is Coach Shaheen Holloway, a legendary player at Seton Hall in the late 1990s who played in Europe for a few seasons, returned to the United States, paid his dues as a high school coach and a low-level assistant at his alma mater and took over the Peacocks in 2018. He’s clearly a rising star.

He kept the bigger, faster offenses of Kentucky and Murray State off balance by mixing up his defenses. The Peacocks run precise, complex offensive sets. They are organized and, in a reflection of their coach, play with toughness. They were physically overmatched in both games, and they will be again against Purdue and its massive frontcourt.

“I’ve got guys from New Jersey and New York City,” said Holloway, a Queens native. “You think we’re scared of anything?”

TALENT RISES IN MARCH: If you want a successful bracket, you could study efficiency ratings, chart box scores and break down matchups. Or you could look at the preseason rankings.

Of the 16 teams atop the Associated Press preseason poll, nine advanced to the Sweet 16, including six of the top seven. Of the seven teams in the top 16 that didn’t make it, three were beaten by another preseason top-16 team. And Baylor, with its best player sidelined, lost to preseason No. 19 North Carolina.

The season exposes teams in good and bad ways – preseason No. 13 Oregon was a flop, and Arizona earned a No. 1 seed from outside the rankings. In more cases, the months between November and March provide ups and downs that some teams are better at navigating than others. North Carolina failed that test for a long while, but by the end the Tar Heels’ talent ensured they would figure it out.

Michigan may or may not have deserved to make the tournament, but once it was in, Hunter Dickinson and a cadre of standout freshmen had a high ceiling. In theory, a No. 11 seed beating a No. 3 seed is a major upset. In reality, preseason No. 6 Michigan beating preseason No. 18 Tennessee is a yawn.

Memphis, ranked No. 12 in the preseason, gave No. 1 overall seed Gonzaga all it could handle Saturday. It took Memphis a while to figure it out, but the Tigers have as much talent as any team in the country. They were a No. 9 seed by résumé. The quality of game they played against Gonzaga would not have been out of place in a region final.

BIG TEN MISERY CONTINUES: Counting Rutgers’ play-in berth, the Big Ten sent nine teams to the NCAA tournament. It will send one more team to the Sweet 16 than the MAAC. Seven Big Ten teams lost on the opening weekend, with only Michigan and Purdue reaching the Sweet 16. Purdue salvaged a horrendous Sunday for the Big Ten during which four teams lost, two of them as the higher seed.

Michigan was the only Big Ten team to make the Sweet 16 last season, when the Big Ten entered March perceived as the country’s top conference. Purdue at least gave the Wolverines company this season.

The SEC may have been worse. Six SEC teams made the tournament. They combined to win four games, with only Arkansas left standing. The SEC carnage included Kentucky’s first-round loss as a No. 2 seed, and No. 2 Auburn falling to No. 10 Miami and No. 3 Tennessee losing to No. 11 Michigan in the second round.

The Big 12 and ACC were on the other side, each advancing three teams to the Sweet 16.

KENTUCKY AT A CROSSROAD: Relative to the rest of John Calipari’s tenure, at least. In a shortened 2020-21, the Wildcats went 9-16 and didn’t sniff the NCAA tournament, perhaps the worst season in school history. This year, Kentucky dominated in the regular season, only to lose to No. 15 seed Saint Peter’s in overtime, clearly the worst tournament loss in school history.

In Calipari’s first 10 seasons, the Wildcats made it to at least the Sweet 16 eight times and never went consecutive years without reaching at least the Elite Eight. Kentucky hasn’t been to the second round since 2019 (although the tournament was canceled in 2020, of course). Calipari has not taken the Wildcats to the Final Four – something he once did four times in six seasons – since 2015. His lone national title came a decade ago.

Calipari never has a problem attracting elite talent, and top-10 recruits Chris Livingston and Cason Wallace have signed for next season. Kentucky also has more resources than just about any program in the country. But Calipari is 63. The next few seasons will determine whether he can return Kentucky to the heights it reached over the first decade of his tenure.

KELVIN SAMPSON has built a powerhouse at Houston. Sampson spent Sunday afternoon shirtless in the locker room, getting doused by the water bottles his players poured and sprayed on him. The No. 5 seed Cougars stormed their way into the Sweet 16 with a 68-53 demolition of No. 4 Illinois, an accomplishment they have made seem routine when it is anything but.

The Cougars have won at least one game in four consecutive tournaments and have made the second weekend in three straight, a stretch that includes a Final Four appearance last year. When Sampson arrived in 2014, the Cougars had been to the tournament once since 1992 and had not won a game in it since they made the 1984 Final Four. They are a March mainstay now, but it should not be forgotten how remarkable that is.

Despite losing Tramon Mark and leading scorer Marcus Sasser to injuries, Houston remained one of the best teams in the country. It crushed Memphis in the American Athletic Conference championship game and is 31-5. If you had to pick the most impressive team from the first weekend, Houston would have to be considered – it smashed dangerous UAB 82-68 and smothered the Illini.

There is nothing fluky about Houston’s dominance, either. The Cougars are second in the nation in Ken Pomeroy’s efficiency ratings, and Gonzaga is the only other team that ranks in the top 10 in both offensive and defensive efficiency. If Houston was not moving to the Big 12, it would be emerging as the Texan answer to Gonzaga: a mid-major that establishes itself as a national force.

MIKE KRZYZEWSKI still hasn’t retired – but he hasn’t faced Texas Tech yet, either. Duke staved off seventh-seeded Michigan State when sophomore Jeremy Roach and freshman Paolo Banchero took over once the Blue Devils fell behind by five with five minutes left. Now things are about to get really hard.

The Red Raiders will test Duke in their Sweet 16 matchup with strengths that align with Duke’s vulnerabilities. Texas Tech opened as a slight favorite. No remaining team can match Duke’s NBA potential, but its stars are mostly freshmen. Experience is the best way to counter Duke’s talent, and Texas Tech starts three seniors and two juniors.

The Red Raiders have the most efficient defense in the country in Pomeroy’s rankings – a swarming, physical man-to-man. At its best, Duke plays beautiful basketball. Texas Tech makes the game ugly. Banchero, a surefire top-five draft pick, and Roach are two of the best shot-makers in the tournament, and if they score, the shooting-deficient Red Raiders will struggle to keep up. But Texas Tech promises to make it hard on them.

Duke is in line to traverse the most difficult road possible, seed-wise, in trying to send its coach out with one last Final Four trip. Overall No. 1 seed Gonzaga and No. 4 Arkansas also advanced to the second weekend in the West.

THE STRIPED NEED to be better. Complaining about the referees is usually tired, but this weekend included debacles that were unacceptable – and not just because across the board college referees act as though they are paid by the offensive foul.

North Carolina forward Brady Manek’s ejection was deserved at best and debatable at worst. But the referees lost control of the game afterward as Baylor used frantic defense to erase a 25-point deficit and force overtime. The Bears fouled incessantly without impunity. Taking nothing away from Baylor’s valiance in attempting to defend its national championship, but it would have been a travesty had North Carolina not recovered and won in overtime.

On Sunday, referee Brian O’Connell gave Illinois’ RJ Melendez a technical foul for hanging on the rim after a breakaway dunk – when all he did was swing himself to safety after momentum carried him underneath the backboard. Illinois would have trailed by four with 8:40 remaining. Instead, Houston nudged its lead to five and regained the momentum. “It’s deflating,” Illinois Coach Brad Underwood said. “You make a play that changes momentum of the game and then to have that called in that moment?”

Late Sunday night, John Higgins’s crew missed an obvious offensive goaltending when Texas Tech guard Kevin McCullar grabbed the rim with his offhand on a breakaway dunk, and in the final minutes the Red Raiders – a challenge to officiate because of their physical style – were allowed to manhandle Notre Dame.