Graham has some numbers on those rankings and upsettings:

First, there's virtually no separation between tiers. Teams that were ranked in the preseason top 10 are 9-9 against teams ranked in the preseason top 25. Teams that were ranked between 11 and 20 are 6-6 in those games. And teams ranked between 21 and 25 are 2-3.

Stunning upsets have earned top billing so far this season -- Nevada beating Louisville, Michigan beating Vanderbilt, Arkansas-Little Rock beating Oklahoma State -- but the war of attrition within the rankings has been just as important in knocking three teams out of the top 10 already (compared to just one at this stage last season).