The idea is that the more often you have up Shield of the Righteous, the more often you will be able to cut incoming physical damage by 30%, which can have a very positive effect on eliminating damage spikes. And while hard-capping expertise may seem extreme, it serves the same purpose as hit and expertise soft-cap in the pursuit of the spike-reduction goal. As Theck said in his first post on this subject,
The real eye-opener here is what expertise does to the large spikes [in the sim]. ... Stacking expertise up to hard cap dropped the frequency of [the largest damage-taken-per-second] spike events by a factor of 10 or more, down to 0.02% or less [compared to soft-capping].
With expertise hard capped (along with hit capped), your HPG attacks cannot be dodged, blocked, or parried, and you are guaranteed the maximum uptime on your Shield of the Righteous buff. What follows is the best protection against the most deadly spikes that you can reasonably manage outside of the wishes-based strategy of going with avoidance gearing.
Remember that the bane of a tank's existence in a raid environment is going to be spikes. Big hits mean that your healers need to go into panic-mode and bomb you with their larger, more expensive heals, which will make it harder for them to make it to the end of the fight with their mana bar intact. Smaller hits over time are far more manageable. Likewise, you are far more likely to die from ill-timed spikes in a short period of time than you are from what has been called a "trickle death" (death by a thousand cuts, so to speak) over a longer period of time/over the course of the fight. In short, total damage reduction is not the way to go.
Ultimately, the name of the game for both you and your healers should be spike prevention. That is the road to more effective survivability.
I agree, this sounds insane after multiple expansion packs of not even thinking hypothetically about that stat. However, Mists of Pandaria
changed that when we were given access to Sanctity of Battle
, which allows haste to modify the cooldown on Judgement and Crusader Strike, our two non-proc HPG abilities. As such, the more haste you have, the faster you can hit those buttons and generate holy power.
One of the benefits of having enough haste, that Theck sees, is being able to cover more hits with Shield of the Righteous (since you'll be able to use it more often). As he writes,
To clarify that thought: thanks to all that expertise, our HP flow is very steady, so we know we'll reliably get a SotR off at fairly regular intervals. For example, let's say we cast SotR to cover the first swing in our 5-swing period. With enough haste we're guaranteed to cover the last one as well. Note that [time between ShoRs] for the exp/haste set is around 6.7 seconds, fast enough that it will definitely cover both the first and last swings in a 7.5-second period. On the other hand, the exp/mastery set only gets SotR off every 7.3 seconds. There will be some variance on that due to CS/J clashes, so there will still be some events where we can only cover one swing of the five-swing period.
He goes on to debate the value between favoring haste or favoring mastery (as those two stats are roughly equivalent). Mastery is better at the 80% spikes in his sims, while haste is better at the 90% spikes -- though, we're talking about probabilities of .3% to .01% here -- it's nonzero, but still noticeable.
The tie-breaker, however, is with regards to DPS. Haste is one of our best damage/threat stats, and if you're the kind of person who cares about your damage output while tanking (or raids in a setting where tank DPS can be a factor) then you will probably find value in choosing haste over mastery. At high Vengeance levels, haste is our best DPS
stat after hit and expertise. Not to mention more haste means more Seal of Insight
procs, as well as more Sacred Shield
So, when it comes to choosing between haste and mastery, your choices are essentially a little extra survivability (.3% more) against the nearly-worst spikes or a little extra survivability (.01% more) against the worst spikes and a chunk of extra DPS. Personally, I think I'll be going for haste.
Is this really worth it for someone not doing heroic raids?
I would argue that it is. If you're doing any degree of raiding, you should care about your damage profile. Even in 10man raids (which I run), I want to be as easy to heal as humanly possible. I want to minimize spikes so that healers don't have to burn through their mana bringing me back from the edge of oblivion. No matter what format of raiding you engage in (aside from perhaps LFR?), you can eat a dangerous spike. This control style of gearing help mitigate that.
It's critical to note that the key to all of this is, as the name implies, control. You need to have control over your rotation, always generating holy power when an ability to do so is available. If you don't think you are doing the rotation optimally, this is not the ideal gearing strategy for you.
Nevertheless, in the end, isn't this all what tanks should care about most? Dealing with and lessening the absolute worst-case scenarios? Our stock and trade should always be cutting off any corner-cases like it's a sheet of paper on the Galactica. Anything you can do to bring your survivability more under your own control is an excellent and worthy goal.
The Light and How to Swing It shows paladin tanks how to take on the dark times brought by Cataclysm. Try out our four tips for upping your combat table coverage, find out how to increase threat without sacrificing survivability, and learn how to manage the latest version of Holy Shield.