On rotation a tail-strike happens more or less only with single-engine ops, as the general upward movement of the A/C will lift the tail out of harm's way for all but the most hearty "tugs" on the wheel. On landing, everything is moving downwards....
The only one I remember at our operation was in a DH8-300 at idle power which was flared for too long. I am glad I never saw the "touched runway" caution light (which wasn't resettable BTW
)