There really isn't a secret to winning the NCAA Tournament. Various people have certain phrases and tropes that they think are talismans to unlocking March Madness.
"Great guards dominate in March!" except for when they don't.
"Experience always prevails!" except when it doesn't.
"Defense travels better than shooting!" and so on and so forth.
Here's the one sure-fire way to win a danged NCAA Tournament, probably: just keep showing up for them. Because if you're there often enough, with a good enough seed (more on that later), eventually you'll get that lethal combination of skill and luck to have the confetti come raining down from the roof of a football stadium in your honor.
Look at Jay Wright! He took Villanova to the Big Dance eleven out of the last twelve years and finally won the dang thing on that 11th attempt. He endured the "JAY WRIGHT CAN'T WIN THE BIG ONE" narrative every time he fell short, kept showing back up, and is now a champion. Do you know why Mike Kryzewski has five titles? Because in nearly 40 years at Duke, he's missed the tournament FOUR TIMES. He's had more than his fair share of embarrassing exits, sure, but he's always back next year.
But just making it doesn't always put you in great position. Statistically speaking, you'll also want to have a team good enough to receive a 4-seed or better. Of the 128 teams to make the Final Four since the tournament expanded to 64 teams in 1985, 83.5% of them had a 4-seed or better. Of the 32 teams to win a National Title in that same time frame, that figure rises to 87.5%. For an event that is seemingly defined by its upsets and the belief that "anything can happen," the bracket's best teams are frequently the ones still standing at the end.
Which brings us to Indiana as it exists under Tom Crean. The Hoosiers floor is simply too low to reasonably expect them to win a National Title. Here is what Indiana looks like during the last six years of Crean's tenure (I'm excluding the first three years, for obvious reasons):
Overall Record: 135 - 66 (.672)
B1G Record: 61-44 (.581)
League Finishes: 5th, 1st, 9th, 7th, 1st, 12th (projected)
NCAA Tournament Appearances: 4
NCAA Tournament Seeds: 4, 1, 10, 5
In only two of these six seasons (and not since 2013) has he guided Indiana to the magic statistical threshold of a 4-seed or better, and it's practically guaranteed that he'll miss the tournament entirely for a second time here shortly. Missing the tournament is not an unforgivable sin, rebuilds and bad years happen, but at a Power 5 program with the history and resources of Indiana University, combined with 36 at-large bids, it's something that should be happening once every five years at most; not twice every six.
Winning the Big Ten is a great thing that isn't easy to do! But that's still only worth one decent shot at a National Title. In their current state, the Hoosiers are seemingly trading their Big Ten titles for two years of basketball purgatory, with effectively no chance at that sixth banner. Sure, the fate of the 2017-18 season has yet to be sealed, but does replacing (at least) the three best players of a 13th place B1G team sound like a recipe to return to the top of the conference?
We always talk about what the expectations at Indiana are, and they vary wildly depending on who you speak to. Personally, I consume far too many probability statistics to ever truly expect a national title, but I think it's fair to expect an opportunity to win a title nearly every year (i.e. just be in the dang bracket somewhere), and frequently being among the top-16 teams in the field. To his credit, Tom Crean has shown the ability to get the Hoosiers in that position, but has struggled to do it consistently. Taking two full seasons to reload and sort yourself out isn't good enough. Particularly after you are given three years almost completely free of scrutiny to resurrect the firebombed corpse of a program.
The Big Dance is a beautiful, chaotic dice roll, and even the favorites face long odds to come out on top. You just don't conquer those odds without several attempts. Just glance at the list of tournament winners going back ten, twenty, thirty years. They're all, almost exclusively, teams that were rattling off multiple appearances with minimal, if any, interruption. Here's a sample: our last ten champions, and their tournament appearances since 2000 (title years in bold):
VILLANOVA: 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2013, 2014, 2015, 2016
DUKE: 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016
UCONN: 2000, 2002, 2003, 2004, 2005, 2006, 2008, 2009, 2011, 2012, 2014, 2016
LOUISVILLE: 2000, 2003, 2004, 2005, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015
KENTUCKY: 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2010, 2011, 2012, 2014, 2015, 2016
UNC: 2000, 2001, 2004, 2005, 2006, 2007, 2008, 2009, 2011, 2012, 2013, 2014, 2014, 2016
KANSAS: 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016
FLORIDA: 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2010, 2011, 2012, 2013, 2014
You can pretty much tack on "2017" to the end of all of these squads (except UConn, probably) as well. Every single team (except UConn, again) was in the tournament the year before they won a title, and many for several straight years before that. Indiana has to find this level of consistency if they ever want to achieve what this fanbase so desperately wants.
Obviously, everyone has their theories about how to best achieve this, some more drastic than others. The bottom line, however, cannot be ignored: in the fairest six-year sample you can provide, Tom Crean, to date, has not been consistent enough for a program that holds itself out to be among the best in the country.