Quote Originally Posted by Aureliami View Post
In every MMO before FF14, theorycrafters took into consideration all forms of mitigation including traits like boost to incoming healing when determining eHP.
No, they didn't. In every MMO before FFXIV, tanks were still defined by 2 different methods of calculating survivability because not all mitigation mechanisms behave the same way. Games that calculate eHP by factoring in mean performance of all mitigation mechanisms rather than discretely separating those mechanisms that increase constant eHP from mean mitigation end up with *loads* of problems (for the last year, Shad/Sin tanks in TOR have been effectively unable to tank anything but 4 man dungeons because they had ~75% of the eHP of the other tanks but the devs thought they were actually *stronger than they should have been* because they were using mean mitigation for eHP). Many games can ignore this by not relying on burst damage as their tank pressuring mechanism so that eHP doesn't actually mean anything so that it becomes all about mean mitigation, but FFXIV is *not* one of those games, as evidenced by fights like Titan and Caduceus with their spike mechanics.

eHP represents the ability to survive spike hits. Where surviving spike hits are concerned, RNG mechanisms, like evasion and parry, and reactive mechanisms, like self healing and increased healing received, do nothing because RNG will inevitably fail and you have to *survive* a hit for reactive mechanisms to do anything. If you average out the performance of mitigation based mechanisms, 20% evasion compared to 20% damage reduction, they'll have the same mean mitigation, but, as soon as the devs put up a spike that's supposed to reduce them to 20% of max hp (like Mountain Buster), the damage reduction will allow the tank to always survive if above 80% hp whereas the evasion tank will simply *die* 20% of the time because it's not active constantly. If you factor in reactive mechanisms, the ability to heal yourself for 25% of your max hp either because that attack will do more than your max hp every single time and you'll just die.

Pretty much *every* MMO has been forced to shift their tank balance paradigm from a single value to 2 separate values. FFXIV *isn't* any different.