Right Slightly ashamed of my previous post so I thought I would explain something that to me seems like common sense but might be missed by some people (ie nubby pug tanks (had one tonight and he/she/it was shamefully sorry excuse for a tank)).Right first some basics that even I understand... deffense rating lowers the chance a player will be critically hit. a tank needs 5.6% to be crit immune 5% for same level and a further 0.2% for ech lvl above that (3 levels above being boss level). What ever way you go about that either through def rating or resi that 5.6% needs to be there... let me explain why:
If i'm healing a tank (lets for a moment assume I'm not playing a drood because things get a bit complicated to explain even though the same is true), tank takes aproximatly x amount of dmg from boss ability #1 and y amount of dmg from boss ability #2. seeing as there is not someone on the boss end face rolling the keyboard these abilities come more or less at regular intervals (some of wich you can even see in super advance due to addons like deadly boss mods). As a healer I know I get a feel for the intervals and know when both x and y are going to hit a few seconds ahead of time and am able to cast a heal in time so when either x or y hit even in close proximity (even when x+y > than a tanks top health) 99 times out of 100 provided I still have mana left the tank is going to live (the likely hood of a tank dying gets smaller as you add more healers all doing the same thing (even smaller with things like reactive heals, hots, and Shields)). This is instinctive healerising and not reactionary healing, and is something that every decent healer learns very quickly (obviously when they are actually depended upon and not just carried by the other 4 healers)
However this all depends upon a tank receiving consistent predictable dmg. As soon as a tank becomes critable there is now a random element to how he/she takes dmg and makes every healer have to do more reactionary healing ("oh fuck the tank just took a big hit that I wasn't expecting, lets heal that, oh know I missed my heal for the next hit, crap the tank is dead!" (this is exaggerated normally but sooner or later most healers will have to move to reaction heals and will fuck up the instinctive heals and then the end is inevitable)).
by not being crit immune you bend your healers over, smack them round the head with a frozen kipper, suck them dry of mana due to excessive overhealing, then more or less inevitably blame them for letting you die.
So for the love of god: stop it! I know having a big health pool is great for pugs but plz, get your deff cap before doing anything else. take green "of Defense" items, I don't care so long as your crit immune!
if you don't believe me go do patchwerk in naxx and watch your getting your 30-40k crits, dying, then getting /spit from everyone in the raid for missing tanking 101.
lots of love your friendly neighbourhood healer!
