Duke coach Mike Krzyzewski couldn't remember the exact moment when he made the switch, or even which game it was. Neither could his players.
According to data from Synergy Sports Technology, the change came on Feb. 11 in an 80-69 win over Georgia Tech. That was when Duke made a nearly exclusive switch from man-to-man to a zone defense. Since that victory, the Blue Devils have played zone 82 percent of the time, compared to 25 percent in the three games that preceded it (two of which were losses).
But the "when" is less important to Krzyzewski than the "why.