Mechanics (Otherwise titled "Hit Capping, Expertise, and you." Written by myself.) Since there are so many questions about hit rating, expertise, glancing blows, etc on the forums, I figure I'll write a little article about them to broaden our understanding of how these mechanics work.
(Keep in mind this is for level cap only.) So, on a mob, there are 5 outcomes of WoW's "one-roll" system:
CritWhite hitGlancing Blow (25%)Miss (28%)Dodge (6.5%)Parry (6.5%)Block (5%) Now, here's where we need to break up the mechanics very simply.
Let's assume you're a rogue in my raid. We have Imp Faerie Fire, which gives 3% hit, or 47.31 (rounded down to 47) hit rating, making the hit cap 316. You meet the hit cap, therefore you cannot miss. You've pushed the miss chance off the table.
So the table now looks like the following:
25% Glancing17% White hit40% crit6.5% Dodge6.5% Parry5% Block Now, let me explain glancing blows. Glancing blows are there, always. There's no way to remove them, there's no way to decrease the chance they happen, they're just there. Always 25% on a raid boss (level 73). This brings in the term "crit cap". Crit cap basically means how much crit you can get before it's worthless and crit strikes start being pushed off the table. What I mean by that is that using our table up there, you've still got 17% of your hits that will be normal white hits. If you get to 57% crit, you're at crit cap. If you get to 58%, you're past crit cap, and now you've got 1% crit falling off the hit table, which is wasted itemization.
You really should never have to worry about the crit cap because of something that we also have to take into account: ROGUES ALWAYS ATTACK FROM BEHIND. I don't give two sh*ts about what the encounter is, but if you're on a boss, you're attacking from behind.
Here's why. This is what our attack table looks like attacking from behind. Same boss, same mechanics, nothing has changed; we JUST MOVED BEHIND.
25% Glancing28.5% White hit40% crit6.5% Dodge Know what the difference is? Instead of that 11.5% parry/block chance, you've now got 11.5% more white hits that 1) aren't glancing, and 2) are doing damage to the mob. Do you see now why rogues always attack from behind?
There's also another difference: when a mob parries your attack, his swing timer is reset. He immediately reaches out and smacks your tank again, possibly killing your tank, or forcing a healer to panic and not heal someone else in the raid.
Now, some more knowledgeable posters may be screaming, "WHAT ABOUT EXPERTISE?!" Yeah, I'm getting to that. First I should note that parry% on bosses is heavily debated right now. It's assumed that it's actually in the range of 12-15%, I just used the old assumed number for my previous examples because it gives my small brain nice easy numbers to work with.
As far as Expertise goes, Expertise rating transfers to Expertise at 3.9 rating per point. 26 expertise will give you 6.5% negated dodge, giving you an attack table that looks like this:
25% Glancing35% White hit40% crit That's now 35% pure white hits. You can see why this is advantageous.
So, there's the end of this little tutorial. Let me sum up by giving you the "front" and "behind" attack tables, along with relevant hit caps.
From the front:
25% Glancing48.5% crit/white hit6.5% Dodge15% Parry5% Block (on mobs that can) From the rear:
25% Glancing68.5% crit/white hit6.5% Dodge0% Parry0% Block Hit cap with 5/5 Precision and
Imp Faerie Fire: 316
Hit cap with 5/5 Precision: 363
Hit cap without Precision: 442
60 Expetise (hitting from the front, negating parry) in rating: 234
26 Expertise in rating: 102
16 Expertise in rating (because of Weapon Expertise): 63