Here at GK Central, we have a slightly different way of looking at top teams. We're not concerned with which squads might be Final Four-bound, or who will finish on top of the conference standings. Instead, we toss and turn at night wondering which Goliath might be vulnerable to a David on the wrong day. And there are some interesting scenarios present at the start of this season.

A host of teams that were susceptible to Giant Killers last season have materialized at the top of the rankings this fall. Perhaps they will feature different statistical profiles with an extra year of experience for returning players and the addition of key freshmen who will change the team's dynamic. But there are enough reasons to worry -- at least based on last season -- and view some of their early-season games as litmus tests for March.

These five teams have something to prove against mid-majors, not just the rest of the top 25.

Indiana Hoosiers

There aren't many questions when it comes to the country's preseason No. 1 team. But from a Giant-Killing perspective, two linger. First, will a team with so much returning talent also feature the same vulnerabilities as a season ago? And second, will coach Tom Crean's gifted group of freshmen be able to fill those holes?