Nifft
Penguin Herder
This."Yes, players know their HP scores. PCs do not."
So don't tell the PC how close the roll was to missing -- tell the player.
It would be annoying if players were required to tell the DM what AC they hit, while the DM was allowed to keep such information secret. This would give a monster with the Wizard template an advantage over a PC of the Wizard class.
Cheers, -- N