[jacobmuller]

Don't know where I read the following but it was probably Kromm:
How come I know when I don’t have to defend?
It's important not to imagine that the defender is standing still and only reacting to a direct and successful attack. This creates a bizarre scene where you know the attack is going to miss and just stand there, and the attacker is whacking at the air beside you in an utterly inept manner.
Just because an attack "missed" doesn't mean you aren't defending. It just means the attack was clumsy enough that any sort of defending was minor and required so little effort that it didn't consume your active defence. It only counts as an active defence if the attack was successful and therefore took enough effort to deplete your defences.
Missing, in the chaos of battle, often means that you failed to anticipate your opponent’s movements and adjust to them, and ended up attacking somewhere he wasn't, grazing his shield or putting your attack where it could be easily and effortlessly deflected. In practice the enemy is moving about (dodging), hiding behind his shield (blocking) and trying to brush aside your attacks (parrying) the whole time.

I'd be delighted if one of you Gurus could correct me.