It's a pretty narrow column on my spreadsheet, but an extremely important one. The heading (T68) is both elegant and cryptic. It's my shorthand for a given team's record against the top 68 in the country at that point in time.
The ingredients of T68 will change throughout the season (home, road, neutral, etc.), as will the composition of the 68 itself. But the bottom line is easy to understand: If you haven't played, and beaten, at least a few opponents in this column, your name won't be among the 68 we hear on Selection Sunday.
This becomes an even more important consideration as the end of nonconference play draws near. We can already determine which potential NCAA tournament teams have it made with respect to "quality wins" and which are putting most (if not all) of their eggs in the basket of league play.