INDIANAPOLIS — Butler did it.

So did Santa Clara, Vermont, Bucknell and Wisconsin-Milwaukee. George Mason redefined the art of the NCAA tournament upset last season with its improbable Final Four run.

For those schools lacking exposure, the NCAA tournament is a chance to show a national audience they can break up tournament brackets from coast to coast.

One win creates a lifetime memory. Two wins makes them a national darling. Four wins puts them in the rarest of classes, mentioned with the likes of North Carolina, Duke, UCLA or Kansas — for one year anyway.

To those who live and breathe mid-major basketball, it takes more than luck.

"I call it the four Cs," George Mason coach Jim Larranaga said yesterday. "First, you have to have great cohesiveness and chemistry. Then you have to have a team that's totally committed to making the sacrifices necessary to win."

"Third," he continued, "you have to be able to communicate on the floor because if you don't, with the crowds, it's easy to get off on a different page. And, most important, is confidence. You have to believe in yourself and your teammates."

What the George Masons of college basketball have demonstrated recently is that they will be more than a speed bump to the second round for those so-called power schools.

Remember Vermont and Bucknell? Or perhaps Hampton and Wisconsin-Milwaukee? Fans at Syracuse, Kansas, Iowa State and Alabama may never forget them.

This year's burning question: Who's next?

Start with experienced teams, winnow the field by finding those that have had success or near success on big stages, look for teams with balanced scoring. Then find teams that have solid guards and backcourt depth.

"You have to have good players, first," Indiana coach Kelvin Sampson said. "Looking back when Santa Clara had Steve Nash, and you look at Arizona's guards. Who had the better player? College basketball is a guards game."

Sampson understands how close those cuts can be. At Oklahoma, in 2001, Sampson's fourth-seeded Sooners lost to 13th-seeded Indiana State in overtime. The next year, Oklahoma reached the Final Four in Atlanta.

Larranaga believes guard play and balanced scoring is critical to short-term success in the tournament. To continue advancing takes solid post players, too.

Teams with postseason experience and dominated by juniors and seniors tend to play better. Take 2003, when Notre Dame survived Wisconsin-Milwaukee's upset bid as the buzzer sounded. The loss helped the Panthers prepare for their next NCAA trip in 2005, and Bruce Pearl's team upset Alabama in the first round and Boston College in the second round that year before losing to eventual runner-up Illinois in the regional semifinals.

This year's field offers a handful of possibilities that fit the model.