Whether you're a die-hard hoops head, a casual or someone who's never watched a college basketball game, there's a decent chance you've been invited to fill out a bracket. Here's what you need to know.

Madness — the NCAA men's basketball tournament — and that means there are going to be upsets. Whether it's a No. 9 seed beating a No. 8 in a kind-of upset, a traditional No. 12 over No. 5 upset or a more stunning upset with a No.

NCAA Tournament officially begins Tuesday and Wednesday with First Four action followed by first- and second-round games on Thursday and Friday as part of a rollercoaster opening week that will see the 68-team field quickly shrink to a Sweet 16 in the span of six days.