Match ups can be huge and sometimes you have an off night, but look who consistently wins in the tournament. Good coaches. The proof that these people are good coaches is solidly in their Ws. its ok to disagree on this, but I feel tourney wins are mostly coaching and in a huge way define their legacy. Most of the great coaches in NCAA history have tournament success.
P.S. Bob Huggins has 29 tourney wins and has 2 Final Four appearances. I'd say he's a pretty darn good coach.