I’ll make this addition to my existing guides later today or this week but: In order to become completely uncrushable you need to have a total of 102.4% avoidance/block(not just 100%). The reason for this is that for each level a mob has over you, 0.2% needs to be subtracted from each of your avoidance/block stats. Just think of it this way: Every point of defense that you have increases all of your avoidance/block stats…it’s something similar with mob hit rating (I don’t think that made much sense but meh, starving).
All Burning Crusade boss mobs are at level 73, that is a 3 level difference. So you need to subtract 3*0.2% from your dodge, defense, parry and miss. That is a total of 4*3*0.2% = 2.4%. So for warriors and paladins, your goal should be 490 defense and 102.4% avoidance/block (with Holy Shield and the warrior equivalent up).
My paladin is currently at 500 defense and 102.5% mitigation/block. The trick is to time your Holy Shield so that it is *always up.* That means, taking the global cooldown into account. I got Crushed to death for 8k ~ 9kish the other week because I timed my spells poorly and had less than a half second where Holy Shield was down. Boo lol.