It was an unusual admission for Duke coach Mike Krzyzewski.Duke's players and coaches often say that defense, above all else, will determine the team's fate. Yet Krzyzewski said Tuesday night that the Blue Devils concentrated on offense during a recent lull when games were spaced 10 days apart."We've been working a little bit more on offense than on defense to get in a better flow," Krzyzewski said after a 113-68 rout of Gardner-Webb.