College basketball rankings: Why Duke jumped preseason No. 1 Kansas to take the top spot in the AP Top 25 poll

In a rare instance of a team losing its preseason No. 1 hold in the AP Top 25 Poll without taking a loss, Kansas fell to No. 2 in the second week of the 2018-19 rankings despite being undefeated.

After thrashing Kentucky 118-84 in the season-opener on Nov. 6, 2-0 Duke is now the No. 1 team in America. The Blue Devils also beat Army over the weekend.

Kentucky falls from No. 2 to No. 10. UK got to 1-1 thanks to its Friday night home victory over Southern Illinois.

Monday's poll is believed to be only the fourth time in the history of the AP rankings that a preseason No. 1 team lost its spot despite not losing the week prior. The most recent instance? It's been 35 seasons. Interestingly enough, Kansas joins a group of bluebloods that have been leapfrogged through almost no fault over their own.

The who-should-be-No. 1 debate is an interesting one. Kansas beat top-10 Michigan State on a neutral floor. It didn't have a second game before this poll came out. Was it deserving of dropping a spot? Was Duke's win over No. 2 Kentucky that convincing?

For voters, absolutely. And it's a refreshing change of pace, as the voting body for the AP Top 25 poll tends to play it conservative when it comes to dropping teams that haven't lost. But in this case, Duke's early returns were so overwhelming, Monday's poll was appraisal of preseason prognostications.

Clearly, slotting Duke at No. 4 in October was too conservative. But Kansas is still receiving No. 1 votes and almost certainly will continue to do so for as long as it keeps on winning. We're very early into the season, but it wouldn't be a shock if the Jayhawks and Blue Devils wind up tussling atop the rankings almost every week for the next four months.

But consider this. If Duke manages to win next week's loaded Maui Invitational, it's conceivable that it won't lose its grip on the top spot for some time. Duke will be the last team in college basketball this season to play a true road game, which won't happen until Jan. 8 at Wake Forest.

For Duke, Monday's No. 1 showing is an AP poll record. The Blue Devils, with this week's ranking, have now stood atop the AP rankings 135 weeks in their history. That breaks a tie with UCLA for most all time. The AP poll dates back to 1949; UCLA had held the record for decades, thanks to the season-over-season dominance during the John Wooden era. Mike Krzyzewski has been coach for 117 of the 135 weeks Duke has held the No. 1 ranking.

Duke's next game is at home against Eastern Michigan on Wednesday night.

Elsewhere in the poll: West Virginia, which lost at home to Buffalo last week, is out. Buffalo -- which made the second round of the NCAA Tournament last season -- hops in at No. 25. WVU and Washington, which lost at Auburn on Friday night, were the two teams to drop out of the rankings. Marquette is new to the poll this week, checking in at 24.