Why Duke is vulnerable

Without Ryan Kelly, can Quinn Cook and Mason Plumlee lead Duke to a championship? Mark Dolejs/USA TODAY Sports

It may seem odd to voice concerns about a team that's ranked No. 1 in the nation in one poll, and a lowly No. 2 in the other. And, to be sure, a lot of observers (and not merely pollsters) seem unconcerned about the Duke Blue Devils at the moment, even as Ryan Kelly continues to sit with an injured foot.

The Blue Devils have helped this mindset along, certainly, by winning their past five games (though that last one, a 62-61 victory at Boston College, was certainly a close shave). At 21-2 overall and boasting lofty ratings even in those perennially skeptical computer ranking systems (currently No. 2 in the BPI, and No. 6 at KenPom), this certainly looks like your standard-issue Duke team. And sure enough, after an initial bout of wobbly play in Kelly's absence, Mike Krzyzewski's team appears to have pulled itself together in its new configuration. I have even heard the term "blessing in disguise" applied to Kelly's injury.

Sorry, but I'm not buying it. I guarantee you Krzyzewski would gladly do without this particular "blessing," because his team's performance has changed significantly without Kelly, and not entirely for the better.

Here's why I'm unconvinced by a Duke team (which plays host to rival North Carolina on Wednesday night -- 9 p.m. ET, ESPN) that right now is being endorsed by pollsters and computers alike:

The Blue Devils owe their high rankings in part to good timing
And I mean "good timing" in both the big picture and the small scale. In the big picture, this is not the strongest ACC we've seen in recent years. The league does rate out as slightly better than it was last season, but both seasons represent a significant dip in quality from what we were accustomed to seeing from the ACC up until about 2011. And while Miami is clearly a legitimate Final Four threat (and Virginia is likely being underrated), the rest of the league is not lacking for mediocre teams.