I considered not mentioning this at all, as it's sort of embarrasing and I know there will be insulting comments about it. I mean, I get insulting comments when I accidentally post that a leather item is mail, or when I don't capitalize an "I" correctly. But it's worthwhile to see how the luck of the draw can make adjustment necessary: I didn't notice I was collecting so much hit gear until I suddenly looked at the sheet and saw myself way over what I needed. Even after throwing Massacre on my two weapons instead of the Titanium Weapon Chain and replacing some gems with Bolds, I'm at 419 hit rating, and I'll keep looking for upgrades that will increase my strength and crit rating. I suspect replacing my gloves alone will solve the problem - at present I've taken the hit enchant off of them for Crusher instead.
Over-reliance on one stat instead of properly balancing for everything you need for a role, whether through sheer happenstance (I honestly didn't intend to stack so much hit) or through a mistaken sense of the stats importance can be very damaging. It's always better to have options, of course. Especially as a tank, you'll need to work on 'sets' for specific fights. One of our tanks has a very high stamina set that still meets the 540 defense needed to keep from being critted but which sacrifices some dodge and parry for block rating and block value. He wears it for Faerlina in the 25 man version as he likes the steady mitigation of Block and the higher health pool for bad luck on an enrage. Other tanks would approach that fight differently, of course (I've not had a chance to tank it yet, but I'm working on a very high dodge set to see if it would be effective) but the point is, don't put all of your stat points in one basket. It's great that you're stepping into heroics with 540 defense already, but if you're at 18k health buffed, then you screwed up somewhere.
This is not saying that defense isn't an awesome stat: in addition to reducing incoming critical hits, it also reduces the chance you will be hit at all, it increases your block, your dodge and your parry chance. It's an awesome stat, but it can't be the only stat you ever look at. I've seen quite a few tanks rolling into heroics with 540 defense and small health pools, low AP, and pretty much no other stats on gear and then wonder why they get creamed. The reason is that defense by itself simply isn't enough. If your gear lacks in Str/AP/Block Value, you won't be generating as much threat, and if you gear lacks in dodge, parry and block rating, you'll simply take too much damage, especially if your gear also lacks in stamina. Please also consider that, for tanking heroics, you only need to reduce your chance to be critically hit against a level 82 mob, not a skull level (effectively level 83) mob. For an example, check out King Ymiron, Meathook and Anub'arak. What this means is, to tank a heroic, you need 5.4% critical hit reduction, not 5.6%. Therefore, to tank a heroic, you need roughly 135 extra defense from gear or 535 total defense, This means that you could have 667 defense rating at level 80 and tank a heroic, rather than the 690 defense rating you'd need for raiding 10 or 25 man content.
Basically, the goal here is not to hit some target number, but rather to know what that target number signifies. Why do you want 540 defense skill/690 defense rating for raids? To reduce the incoming critical hits to zero so that your healer won't have to work as hard. Well, if you can achieve that with 535 defense skill/667 defense rating for heroics, you should do so, and then instead of working for uncrittable against level 83 mobs (which you won't be tanking in a heroic) you should make sure to get more stamina, more mitigation and more avoidance via gear choices, and possibly also selecting for threat. It's a balancing act, yes, but it helps to keep in mind what you're actually trying to achieve rather than just aiming for a number. It also helps if you pay attention to how much the new gear your getting has of a specfic stat rather than being surprised by how much hit you have one day when you put all of your new set together. I'm looking at you here, Rossi. The point of all that hit is to reduce the miss rate on your specials, it's not some sort of manta you chant until the bosses die, and you need other stats like strength and critical strike rating to make the most of your damage. Not even mentioning Expertise, which is very valuable until soft-capped to get rid of those pesky dodges. (Unlike a tank, a DPS warrior only needs to worry about dodges, as you should be attacking from behind.)
Effectively, what you have to consider is that, while you could stack one stat to the exclusion of all others, and you'd still continue to get an improvement up until a ridiculously high number (in the case of hit rating) or even possibly forever (there's no upper limit on the .04% to dodge, block and parry per point of defense skill, it could keep accruing forever in theory), focusing on any stat to the exclusion of all else is not effective when you take the whole of an item's budget into account. You can get more from straight block rating, dodge rating or parry rating on selected pieces of gear than you will from just stacking defense, for instance. So make sure to try and keep your gear selection properly balanced and don't pull a Rossi, forcing you to run around re-enchanting and gemming all of your gear to make up for your short sightedness.
Next week: 10 man gear.