My setting is all TUF and I am running best in bag sim. That stats the following:
Less Crit
Less Haste
More Mastery
Less Vers
Optimal Stats are like 99% Mastery, fine so far.
But up on gear selection AMR tells me to enchant my stuff with crit and also place crit gems in my stuff.
How comes that? Is there a minimum crit threshold that should be reached?
One or another element seems broken here.
What should I trust?
Well, both. 
The data on the right shows which stats to go for, i.e. “generally speaking, getting gear with thoes stats simulate better than your current gear”.
The BiS function only uses gear you currently own and gives advice for that specific situation.
Gearing currently includes so many different factors that it’s not possible to give general advice like “haste is always better than crit” or “never use versatility” as there’s far too much interaction between stats. While there may be an optimal stat distribution that doesn’t necessarily mean other options are bad.
You can click on the “View optimal stat graph” on the right to get an overview of lots of different stat distributions with tooltips showing how big the difference would be.
If I take a look at the current recommendations for my blood dk, there’s less than 1% simulated difference between having 3000 and 800 mastery. As I’m unable to reach 3k mastery, gearing for another value gets recommended but the data on the right will show “you may want to get more mastery”.
Thanks for your answer, but here is the stats graph:
It looks like “every single stat should be mastery”, or not? I can’t see the point where the increase of crit should increase my TUF.
You mean I am at that spot of mastery where crit would increase my TUF (red area)?
That could change with each mastery point I gain, so for me it makes more sense to go for mastery.
The stat graph and the stat analysis are meant to give you a quick visual overview – there are a lot of other stat combinations that will perform very similarly to each other that are not depicted on the graph.
With your particular gear and settings, there’s probably a balance of crit and mastery that works out a bit better than stacking mastery to the exclusion of all else.
Regardless – it won’t make much difference if you went for more mastery instead of crit in your case. Your performance in-game will be roughly the same.
You can use our new customization features to nudge the optimizer towards a higher mastery build if you prefer it – go to the customize tab, turn on the secondary stat section, and move the dividers between the pieces of the pie to change how much of each stat you’d like the optimizer to go for.
Thanks for your answer.
