Has anyone ever figured out exactly how arcane mastery works

[Heartfrost]

It increase your damage done based on the amount of mana you have left Pretty straightforward, but in what way is the damage buff decreased when your mana goes down. Is is for every 1% of your mana pool you lose you lose 1% of your damage buff? Is it you have the full buff to a certain % of mana like at 79% you lose 20% of your damage buff.

I want to know the correlation between the buff and your amount of mana left.

[Shangalar]

The first thing you said. The number on your character sheet when you're at full mana (for example 20.2%) is only when you are exactly at 100% mana. The drop is linear from 100% to 0%.

[Rotted]

Totally not sure, but when I was doing research on how to play arcane properly the rotation was along the lines of

6 Blast
Arcane charge is it? (Early morninig )
4 Blasts
Arcane Charge
4 Blasts
Arcane charge
Mana gem,

Rinse repeat 2 more times,

Then carry on with the same rotation until you hit 1/4 of your base mana, and then pop evo,

This was apparntly the most effective dps rotation to keep your mana high most of the time, I'll have a look through my history when I get back to see where I read it, but if its right, then I'd guess the author has the answer to your question somewhere on his info

[Soulstrike]

say you have 50% damage increase from mastery

you will do 50% more damage at 100% mana

you will do 25% more damage when you are at 50% mana

so when you are at 99% mana you will do 49.5% more damage