You can always just drop expertise untill you do get a parry and then twitch the number a bit until it stops again
So i was bored and i started to switch tanking pieces to dps ones in heroic, and now im interested how much expertise is needed for heroic instances, not raids (raids should have 14%) to eliminate parry. I was running thru few instances with 41 expertise (10,25%) and didnt got single parry. Anyone knows exact numbers so i could possible lower expertise a bit more if its not needed?
lvl 80 (5%)
lvl 81 (5,2%)
lvl 82 (5,4%)
The Caps are for Dodge and Parry.
As far as I remember, each level increase is a 0.5% increase, so lvl 83 needing 6.5% (for dodge) a level 82 boss needs 6%. As for parry, I would think its 13.5% which would be 54 expertise, but I'm not sure if it works in the same way as dodge with level scaling.
Lythos is correct.
Generally speaking the scales take small consistent steps for 1-2 levels of difference, and a big step for 3 levels difference and above.