The Associated Press

So much for the little guy. Big boys like defending champion Florida and No. 1-ranked Ohio State are among the top-seeded favorites, while the darling mid-major teams get surprisingly few chances to turn the NCAA tournament into a free-for-all for underdogs.

March Madness officially began Sunday when the pairings were announced, kicking off office and online pools and triggering debate about seedings, who went where and who didn’t make it at all.

Florida will try to become the first team since 1992 to repeat as champion — and the first ever with the same five starters — and the Gators will do it with their first overall top seed in the tournament, leapfrogging Ohio State courtesy of three straight routs in the Southeastern Conference tournament. North Carolina and Kansas were the other No. 1 seeds, rounding out a group that all won both their regular-season and conference tournament championships.

‘‘It’s a compliment to our season as a body of work,’’ said Florida coach Billy Donovan, whose team rebounded to finish 29-5 after losing three games at the end of the regular season.

Still, it’s hardly a guarantee the Gators will be in Atlanta for the Final Four on March 31. Last season, they won it all as a No. 3 seed, and not a single top-seeded school made it to the Final Four for the first time since 1980.

Falling to a No. 2 was last year’s national runner-up, UCLA, which looked headed for a No. 1 seed until losing its last two games, including the quarterfinals of the Pac-10 tournament.

But the real surprise came in the meager number of at-large bids handed out to mid-major teams. Only six of 34 spots went to the little guys, down from eight last year and 12 in 2004.

It means fewer opportunities for a repeat of last year, when 11th-seeded George Mason — the commuter college in Virginia — struck a blow for the underdog in a stirring trip to the Final Four.

‘‘Last year, the impression was that the tournament committee had gone overboard in selecting mid-majors,’’ selection committee chairman Gary Walters said. ‘‘But when we start the process, we throw conference affiliation out the window … and it shakes out where it shakes out.’’

While their sheer quantity wasn’t impressive, some mid-majors thrived in other ways. Southern Illinois earned a fourth seed and Butler a fifth. Meanwhile, Big South champion Winthrop and America East champion Albany were seeded unusually high at 11th and 13th, respectively.

Parity reigned this year with a record 104 teams winning 20 games or more and a record 48 teams appearing in The Associated Press Top 25, raising the possibility of a mid-major revolution when the brackets came out.

It wasn’t to be. Instead, the final five bubble spots went to Arkansas, Illinois, Stanford, Purdue and Texas Tech — all from power conferences.

The Atlantic Coast Conference placed the most teams in the tournament with seven, while the Big East, Pac-10 and Big Ten had six each, the SEC five and the Big 12 four. No mid-major had more than two.

Old Dominion of the Colonial Athletic Conference did get an at-large bid, but Missouri State (0-5 against the top two teams in its league), Air Force (season-ending four-game losing streak) and, maybe most stunningly, Drexel (finished behind Old Dominion and Hofstra in the CAA), were left out.

‘‘It’s very disappointing, not just that you didn’t get in, but when you look at some of the teams that did,’’ said coach Bruiser Flint of Drexel, which went 23-8 with 13 road wins.

Little guys weren’t the only ones disappointed.

Kansas State looked safe in Bob Huggins’ first year as coach but didn’t make it. Neither did Florida State. And the biggest surprise of all might have been to bypass Syracuse, 22-10 and winner of seven of its last 10.

‘‘I have no way of understanding why we’re not in the tournament,’’ coach Jim Boeheim said. ‘‘You look at the numbers and it’s hard to believe. But it’s done. There’s no use in talking about it.’’

Other notables from Selection Sunday included:

— Lute Olson of Arizona making his 23rd straight appearance in the tournament, tying the record held by Dean Smith at North Carolina.

— Louisville getting a nice break, earning only a sixth seed, but having to travel only an hour down Interstate 64 to play in Lexington’s Rupp Arena, home of rival Kentucky.

— A very angry Niagara team, relegated to Tuesday night’s play-in game against Florida A&M despite a 22-11 record that included an 11-game winning streak.

‘‘Nothing makes sense to me,’’ coach Joe Mihalich said. ‘‘Let me be diplomatic here — I’m confused.’’

— A first-round matchup between Marquette and Michigan State pitting former Spartans assistant Tom Crean against his old boss, Tom Izzo. A possible second-round matchup between Illinois coach Bruce Weber and his former assistant at Southern Illinois, Chris Lowery, who moved into Weber’s spot a year after he left.

‘‘I don’t think it’s a coincidence, no,’’ Weber said.

— A possible Pittsburgh-UCLA matchup in the West Regional that would match Bruins coach Ben Howland against the team he left. UCLA’s first-round matchup is against Weber State, Howland’s alma mater.

— Top-seeded Florida, best team in the South, moved to the Midwest Regional, where it would have to play in St. Louis; Ohio State, best team in the Midwest, placed in the South Regional, where it would have to go through San Antonio.

‘‘When we looked at the mileage, it was a little bit of a push,’’ Walters said. ‘‘St. Louis seemed like a more natural area for Florida to go.’’

The Gators defeated Ohio State 86-60 back in December, but that was before sensational freshman, Greg Oden, was a factor for the Buckeyes; he was just coming back from a torn ligament in his right wrist. Walters said it wasn’t so much that victory, as Florida’s overall performance this season, that led the committee to list the Gators as the top team.

‘‘That was a decisive victory,’’ Walters said. ‘‘But one has to acknowledge that Ohio State was, at that time, just getting Oden into the mix. I think Billy Donovan would be the first to concede that Ohio State is a very worthy first-line team.’’

At first glance, the East Regional seems to be the toughest. There, North Carolina earned its record 11th top seed, but second-seeded Georgetown has won 15 of 16 and fourth-seeded Texas is led by freshman Kevin Durant, who might be the best player in the country.

‘‘We should have some confidence from winning the ACC tournament, but as I’ve always said, you build your momentum in the NCAA tournament,’’ Tar Heels coach Roy Williams said.

The easiest path? Maybe its Florida in the Midwest, though nobody would relish that possible second-round matchup against Olson and Arizona.

All that’s debatable, as was the committee’s decision to offer so few spots to the underdog teams that have put so much of the madness into Marches past.

‘‘It would be the height of arrogance to say we get everything 100 percent right all the time,’’ Walters said. ‘‘I’m not suggesting that not selecting Drexel isn’t the right decision. But I am suggesting if you put 10 people around a table, one could come up with different results.’’