Damage mitigation (T6 mastery)
While I get that defense has diminishing returns, what that specifically means for reduced defense in the context of this game is still unclear to me (largely because I don't know what values correlate to what damage reduction values). Specifically, I'm looking at when helmsmasher would be more useful to have as opposed to flawless execution for Skullcrown. I get that helmsmasher only has 50% chance of activating, and it would only take off of current defense (so the target would have an effective defense of 30%), but what does this even mean for damage as opposed to the flat 20% crit damage?
Using an arbitrary number of 2000 defense (which may or may not be realistic), this would mean using helmsmasher each attack would result in doing damage on an enemy with 600 defense when it procs. Does anyone know the effective damage reduction from 800 defense compared to 600 defense so that I can figure out if this would be arguably more beneficial or not (or whatever values would make sense) or shed more light on this topic? Searched for a bit and couldn't really find anything that helpful, and from my days as a kitty during wrath I know armor and defense mitigation is a super fun topic so..... any help appreciated!