If you believe that your damage per second (DPS) isn't quite where it should be, and that you should be pulling higher numbers than you are, then one of the first things to look at is whether or not you are at, or above, the various stat caps. One of the keys to maximising your DPS is to make sure that you are hitting the enemy as often as possible. Obviously if you are swinging, or shooting/casting, and missing 50% of the time, your DPS is going to be significantly lower than if every attack is a direct hit. Making sure that you are constantly capped can be a tough balancing act, particularly if you are upgrading gear frequently. Here are some of the key stats and caps you need to keep in mind when swapping gear.

Before we start, when people talk about a 'cap', they are usually referring to the point at which acquiring more of that particular statistic will provide no additional benefit.

The Hit cap

The hit cap usually refers to the point at which you have sufficient hit rating so that your attacks will never miss a raid boss. Your first aim should be to collect enough hit rating so that your special attacks are always hitting their target, as each time you miss you are effectively losing DPS as well as wasting whatever mana, rage or focus you used for that special attack. While hit rating may not sound as sexy as say 'strength' or 'agility', in almost all cases, if you are under the hit cap, hit rating will do the most of any stat to improve your DPS. Hit rating affects your chance to hit with auto attacks (both main hand and off hand if you can dual wield), special attacks and spells.

The 'soft' hit cap the point at which your yellow, or special, attacks will always hit. Any more hit rating above the 'soft' cap will have no effect on your yellow attacks. The 'hard' cap is the point at which your auto attacks will always hit and more hit rating does absolutely nothing for you.

Starting out you have an 8% chance to miss a raid boss when using a special attack. So to reduce this 8% chance to miss you need approximately 262.32 (rounded up to 263) hit rating. You can reach this figure from hit rating on your gear as well as through taking class specific talents such as Precision, as well as the uniquely titled, Precision.

For some classes (eg. Hunters) once you reach 263 hit rating there is no point in actively chasing more hit as your chance to hit with a ranged weapon is at 100%.

For classes that dual wield for the purpose of dealing melee damage - for example rogues and fury warriors - the hit cap is a massive 886 hit rating. In other words you need 886 hit rating to ensure that all your auto attacks hit with main and off hand weapons. At this point in the game it is not advisable to stack this much hit rating as in doing so you'll be effectively crippling your DPS through compromising other key stats.

For classes that deal spell damage - this includes Death Knights and Rogues (as poisons are considered spell damage) - you need 446 hit rating to ensure that the spells hit their target.

The stat priority for all classes should be to reach 263 hit rating to ensure that main hand attacks and special attacks hit. For classes that deal spell damage as well, 446 hit rating should be the target. Once you reach those two targets - depending on which is more appropriate for your class - you should begin chasing other stats appropriate to your class.

If you're stuck trying to figure out what hit rating you should be aiming for with your combination of class, race and buffs check out the hit calculator here, it's quite handy.

The Expertise cap

For melee classes reaching the expertise cap is the second highest priority. Raid bosses have a 6.5% chance to dodge and a 14% chance to parry melee attacks. While a boss can only parry an attack that comes from the front they are still able to dodge attacks even if they come from behind.

As a general rule, melee DPS should only ever be attacking from behind the boss. This removes the chance that the boss will parry the attack and also potentially reduce the damage melee DPS take. With that said, even if melee DPS are in the perfect position, there is still a 6.5% chance that the boss will dodge their attacks. To remove the bosses chance to dodge, melee DPS need to stack expertise. For properly position DPS there is no point stacking any more than 26 expertise as you will see no additional benefit over and above that figure.

As parry should not really impact melee DPS, the expertise soft cap that melee DPS must reach to remove the chance the boss will dodge and attack is 26 expertise (or 214 expertise rating). Depending on your class you may be able to take talents to boost your expertise, reducing the amount you need to gem for. For example, combat Rogues can take two points in Weapon Expertise, increasing their expertise by 10 and Enhancement Shamans have Unleashed Rage which increases their expertise by 9. Paladins can get away without gemming for Expertise by using the Glyph of Seal of Vengeance - or Corruption if you're a Blood Elf - that increases the Paladins expertise by 10 so long as Seal of Vengeance is active.

The Armor Penetration cap

The Armor Penetration cap (or ArP cap) is a slightly more complicated beast, and one deserving of it's own post. Fortunately here's one I prepared earlier:

Demystifying armor penetration

In summary

Like I said up front, making sure you are capped can be a difficult balancing act, although it does get easier as you move into some of the higher level gear. In almost all cases, if you are sitting below the caps, particularly the hit cap, stacking stats to reach the caps will have more impact on your DPS than any of the other stats available to you.

p.s. If you're interested in the Horde cap I used as the icon for this post you can find it here at Jinx.