Duke played so many games in the first two weeks of the season that coach Mike Krzyzewski's team had relatively little time to refine itself on the practice court. The Blue Devils (No. 5 ESPN/USA Today, No. 7 AP) are starting to get that chance. Freshman guard Austin Rivers scored 17 points to help Duke beat Colorado State 87-64 on Wednesday night, a successful return from a week-long break following a lopsided loss at Ohio State.