When does tippet strength become strong enough that 20lb dacron backing (or the backing to flyline knot)becomes the weakest link when all the fly line is out of the rod? For instance, if tippet rating is 14lbs does one need to be a little careful how much pressure to exert on a fish when all the flyline is out of the rod and the backing is 20lbs? Breaking off a tippet is one thing but breaking off a flyline is quite another.

Thanks,
Ole