Mastery rating on gear

A quote from Eyonix a couple of months back:

Here’s how the system works: As you spend points in a given talent tree, you’ll receive three different passive bonuses specific to that tree. The first bonus will increase your damage, healing, or survivability, depending on the intended role of the tree. The second bonus will be related to a stat commonly found on gear desirable to you, such as Haste or Crit. The third bonus will be the most interesting, as it will provide an effect completely unique to that tree -- meaning there will be 30 different bonuses of this nature in the game. This third bonus is the one that will benefit from the Mastery rating found on high-level (level 80 to 85) gear.

Protection warriors have three masteries at present

- Damage reduction
- Vengeance
- Critical block

According to MMO-champion's Cataclysm warrior preview, the damage reduction is capped at 8.01%, and vengeance (hereafter referred to in this blog as "venge") is capped at 5% damage taken. This leaves critical block chance as increasing depending upon the amount of the mastery stat on gear.

Here's a picture of some new gear with mastery on it.

So what does mastery do for prot warriors then? Well, it's block value, essentially, isn't it? It makes our blocks bigger. It is therefore useless against spell damage and against bleeds, and it is RNG-based. With block now mitigating a fixed percentage in Cata it may be that larger blocks are valuable - certainly I normally block 2-5k damage per hit, whereas if the Cata block model was used I'd be blocking around 5-10k. To a certain extent the value or otherwise of RNG-based mitigation stats such as block and dodge will depend upon whether or not Blizzard's new healing model works.

The new healing model is for the tank not to be in immediate danger of dying in a 4 second window, so casters can wait to see if the tank takes a hit before deciding whether to heal. Healers therefore don't need to be spamming the tank constantly or at least can be using a small, mana-efficient heal rather than a powerful, expensive heal. If that's right then block and dodge might be useful, and mastery as a stat might be desireable.

Currently though it looks as if I'll be searching for stamina and armour on my gear, rather than mastery rating .