When the NCAA Tournament reaches the Sweet 16, that means there are only 15 games left to decide a national champion.
Kentucky needs to win four of those games to become the first undefeated champion since Indiana in 1976. The Wildcats improved to 36-0 - the best start to a season for any team - with a workmanlike win over Cincinnati. Next up in the Midwest Regional semifinal is West Virginia, another team that will come right at Kentucky and try to force turnovers, the Mountaineers' trademark this season.
The East Region changed dramatically entering the Sweet 16 with top seeds Villanova and Virginia ousted. It's the first time since 2004 - and eighth time ever - that the top two teams from one region failed to advance to the second week.
The Atlantic Coast Conference and Pac-12 entered the round of 32 as the only leagues with three or more teams not to lose a game. The ACC is 11-1 with Virginia's loss to Michigan State the only blemish. The Pac-12 is 7-1 following Oregon's loss to top-seeded Wisconsin.
Here are some story lines to watch as the Sweet 16 approaches:
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REMATCH REPLAYS: Two of the eight games in the regional semifinals will be rematches from the regular season.
UCLA and Gonzaga met on Dec. 13 in Los Angeles, and the then-No. 9 Zags came away with an 87-74 victory. Kyle Wiltjer scored 24 points and Byron Wesley added 20 points for Gonzaga.
Bryce Alford scored 23 points and Isaac Hamilton added 18 for UCLA.
Louisville and North Carolina State met in an ACC game on Feb. 14 and the visiting Wolfpack prevailed 74-65. Cat Barber had 21 points for N.C. State, which held Louisville to 33 percent shooting and outscored the Cardinals 32-16 in the paint.
''We got dominated at all five positions tonight,'' Louisville coach Rick Pitino said then.
Chris Jones, who was dismissed from the program last month, scored 20 points and Wayne Blackshear added 19 for then-No. 9 Louisville. Terry Rozier and Montrezl Harrell, Louisville's leading scorers, combined for 14 points.
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SWEET SEEDS: The West Regional will be the toughest of the four in the Sweet 16 if you believe the seeds.
Top-seeded Wisconsin will play No. 4 North Carolina and second-seeded Arizona will face No. 6 Xavier in Los Angeles, a total of 13 when the seedings are added.
The Midwest is second with 16 (No. 1 Kentucky vs. No. 5 West Virginia and No. 3 Notre Dame vs. No. 7 Wichita State), while the South is next with 19 (No. 1 Duke vs. No. 5 Utah and No. 2 Gonzaga vs. No. 11 UCLA).
The last of the regionals is the East where third-seeded Oklahoma meets No. 7 Michigan State and No. 4 Louisville faces eighth-seeded North Carolina State, a total of 22.
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SPECIAL K: When the coaches shake hands before the Duke-Utah Sweet 16 game, it will be between two men with a lot in common.
Duke's Mike Krzyzewski and Utah's Larry Krystkowiak probably lead the NCAA in name typos.
''I don't know how many times two Polish coaches will go against one another, where both of us are called Coach K, but he's a good friend,'' Krzyzewski said of Krystkowiak. ''I had him on my Sirius XM show about a month ago and, boy, he was really good - really good.''
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SPARTY'S PARTY: Michigan State under Tom Izzo has become as familiar in the Sweet 16 as the guys in a school band wearing enough face paint to cover a garage.
The Spartans have reached the regional semifinals for the seventh time in the last eight years. They will face Oklahoma in Syracuse, New York.
Izzo has a 13-1 record in games in the round of 32. He was surprised a bit that this team won its second game to move on.
''We've been a team all year that has banged around, probably lost more games than we should have just because of the free-throw situation or dumb coaching with 2, 3 seconds left to go in the game and people hitting 3s and tying it,'' Izzo said. ''But I think we've had to earn every single thing we've gotten because every game's been like that. So I think they felt comfortable in a game because that's the way not their whole tournament has gone or the Big Ten Tournament, their whole season has gone that way. I'm really proud of this team. I don't use that word lightly when I speak and I am.''
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KENTUCKY'S CHASE: The top-ranked Wildcats showed in the round of 32 why they are the even-money favorite to win the whole thing.
In their win over Cincinnati, the Wildcats shot just 37 percent and were outrebounded 45-38. There really wasn't a point in the game when Kentucky felt threatened about its winning streak and the 64-51 win was the Wildcats' 29th of 36 by at least 10 points.
''I always like it when my team shoots 37, 36, 35 percent and wins in double digits,'' Kentucky coach John Calipari said. ''It shows them they don't have to make shots to win. You can miss them all. No, you can't miss them all. You can miss most of them, and you can still win games if you defend, you rebound and you play that way, make your free throws, and they did.''
