Though some fans have barely shaken off Winter Olympics fever, a new two-week sports frenzy begins Tuesday -- one that comes every year, not every four. Teams were selected Sunday, based on 2009-10 records and some wild-card spots, for a National Collegiate Athletic Association basketball championship series that will winnow 65 teams down to a Sweet Sixteen, then an Elite Eight and ultimately a Final Four for April 3-5 games in Indianapolis.

It's called March Madness, which also covers last week's conference tournaments such as the Big East, Big West, Pacific 10 and Big 10. For college students, alumni and basketball fans worldwide, this is It. Many fill in "bracket" grids, trying to pick each round's winners -- often with a betting pool involved. Live streaming of games online and to mobile devices makes it easier to sneak peeks in school, at work or nearly anywhere. Studies suggest that business productivity slumps at least a bit during the next two weeks.

There's extra buzz this year because a tournament expansion to 68 or even 96 teams is being considered to let the NCAA earn more TV revenue and bring in teams that nearly qualify now. Coaches generally support expansion, but fans are strongly opposed. In a USA Today poll, 80 percent chose "the field of 65 is just right." That size has been in place since 1985, and New York Times sportswriter George Vecsey also feels it's ideal. "Don't get too greedy," he told the NCAA in a column this month.

Broadcaster says: "It's always wide open, but this year -- more so than the past couple years -- it's even more wide open. You look at the top seeds . . . All these teams are so vulnerable." -- Jay Williams, ESPN analyst and past Duke University player

Blogger says: "Don't try to fix something that isn't broken. There's a reason complaints about the format of the Tournament are so rare. It works." -- Kevin Pender, Houston Chronicle sportswriter and blogger

Casual fan says: "I don't really start getting into it until the Final Four. Once it's down to the end, I'll be watching more closely." -- Larry Lynch, construction worker in Hull, Mass.