Are my mitigation numbers off ?

[Jpec07]

Isn't Parry useless when Block procs ? Meaning that DRK and WAR also gain more than PLD from stacking Parry.

Yes, my calculation assumes 100% usage, with a little "generous" part for PLD. With shorter and more frequent mitigation, I think it'd only widen the gap in favor of WAR.

It is, so you'd need to include that in the calculation as well (since the interplay between block rate and parry rate is complicated). So effectively, a parry rate of 25% would only affect those physical hits that couldn't be blocked, so (100-{blockRate})% * {parryRate}%. Assuming 25% for both, that's 25% of 75%, or 18.25% (times .2 is only 3.65% mitigation, versus the 5% it would have been otherwise).

Mind, I'm not disagreeing, I'm just a little bit of a math nut, so number charts fascinate the hell out of me. XD

What also needs to be considered is the affect of WAR stacks in Determination that stack 4% every 2.5s up to +20% Parry. Hand in hand with this is the amount of time a WAR spends between hitting their instawrath button and whatever they use it on. Self-heals are also a component here that should be considered, since they contribute to total mitigation.