I have seen coaches go man-to-man anytime the point guard made the first pass to the right side, and go 2-3 zone whenever that first pass went to the left side. Some coaches will change defenses after a made free-throw, or after a time-out, or will call out defenses from the sideline. The only thing about all this… in trying to confuse the offense, you have to make sure your own players aren’t the ones who become confused!
Like selecting an offense, select a basketball defense(s) that best fits your team’s personnel, size, quickness, and strengths, and your own defensive philosophy. Some coaches stick to the same defense all season and try to perfect it. Other coaches will try multiple defenses, not only throughout the season, but within a game, switching between man-to-man and zone defenses, trying to confuse the opponent, and trying to stop the offense’s strengths.