INDIANAPOLIS — No one told basketball purists you’re not supposed to mess with a Hollywood script.

As most everybody characterizes Butler’s run to the national championship game as a Cinderella story and tonight’s game against Duke as David vs. Goliath, basketball insiders say get the story straight.

Yes, Butler is a first-time Final Four team and the first school from the Horizon League to get this far. Yes, Butler is a small school (enrollment 4,200) with a home court that has a rich basketball history. Yes, parts of the movie “Hoosiers” were filmed in Hinkle Fieldhouse.

Throw out the script and read the scouting report.

These guys are good, very good. The front of the jerseys read Butler, which just happens to be the No. 11 team in the AP Top 25.

This is not George Mason.

“In order to achieve what Butler has, it’s something that doesn’t happen overnight, not in just a year,” said Jim Larranaga, coach of the George Mason team that shocked college basketball by reaching the Final Four in 2006 as a No. 11 seed. “It’s a level of success that comes over a lengthy period of time.”

This is the fourth straight year the Bulldogs have been in the NCAA tournament, and this is the second time in that stretch they’ve been a No. 5 seed. That means the committee had them in the top 25 teams in the field.

Butler has been in the NCAA tournament 10 times, and it reached the Round of 16 in 2003 and 2007. Including this year, the Bulldogs have won 10 NCAA tournament games since 2001.

“They don’t have the same players and coach every year, but there is a system in place there,” Larranaga said Sunday. “I’m not saying what we did was a fluke, but what we did is only similar in that it was two programs operating at a very, very high level of competition compared to the high majors on a lot less of a budget.”

Duke was ranked as high as third this season and never fell below 10th. Butler was ranked 11th and is on a 25-game winning streak. The Bulldogs’ non-conference schedule was deemed the toughest in the country by the computer ratings.

“What makes our run so special was the programs we beat along the way – Michigan State, North Carolina and Connecticut were all previous national champions,” Larranaga said. “Connecticut started five NBA players. We were a true mid-major with no NBA players.

“Butler has Gordon Hayward and Shelvin Mack, who will play in the NBA. We did it truly as a team, and we didn’t play real slow either.

“It’s not a surprise what Butler has done. They were 11th in the preseason poll and the top 15, 20 teams have a shot to get to the Final Four.

“To win a national championship you have to get lucky, get a break or two. That program has been on par with a lot of the high majors for an extended period of time.”

Maybe we should blame the term mid-major. It means a team from a non-Bowl Championship Series conference. So if you don’t play in the Big East, Atlantic Coast Conference, Southeastern Conference, Big Ten, Big 12 or Pac-10 you’re a mid-major. But there are exceptions. Butler is one just like Memphis in 2008 or Marquette in 2003 or Utah in 1998 or Massachusetts in 1996.

Some schools just don’t deserve the mid-major tag. There are great basketball programs that just don’t happen to have big-time football teams. Try telling UNLV that, when it won it all in 1990 and came within a last-second shot of possibly repeating.

“UNLV, according to my thinking, was not a mid-major in the 1990s when it was No. 1 in the country,” Larranaga said. “Everybody thought Gonzaga would be the one to break through. But it was Butler.”

So save the fairy tale comparisons and the Hollywood endings. It’s Duke vs. Butler. It’s either one major program getting its fourth national championship or another major program getting its first.

Just ask Duke senior guard Jon Scheyer if it’s David vs. Goliath.

“For us, it’s not how we look at it at all,” he said. “They’ve been a top-10 team the whole year. We know how great of a team they are.”