Threat: Expertise vs Strength (gemming)

[Lenox]

Not that I would ever gem for strength, but I have seen some do it. And it's made me wonder, what is the relationship between the amount of threat you put out between strength and expertise (rating) for a warrior tank (other tanks are welcome also)? Since the food buffs are 40, let's compare 40 expertise rating to 40 strength.

Additionally, I know expertise provides a value other than threat. Let's not mention that for purposes of this discussion. This is a discussion about threat. Mentions of damage (dps increases from either stat) and mitigation (strength to SBV conversion) are also valid.

[Satorri]

Well, for what it's worth, Expertise will increase your chance to hit by double the amount hit rating will up until you hit 26 expertise on the sheet, for almost every move you rely on for threat.

Strength will increase the damage, but the application of both gets sticky as you have to trickle it down through every ability, and appreciate how much each ability contributes to your total threat.

As a tank, if you're concerned with threat, I'd first make sure that you are at or above 26 expertise before even considering looking at Strength. After that, you can still stack Expertise and have fine effect.

If you want to talk specifics, it gets a lot more time consuming to work out the total effect of each.

[Edgewalker]

For 99% of situations gemming for expertise will be the better choice overall for threat in my opinion, and 100% of the time before you hit 26. The advantage of not being able to miss at all has a lot of application for snap threat as well.

[Satorri]

Few things suck more than missing that big Shield Block/Shield Slam when you charge in...

[Synapse]

Few things suck more than missing that big Shield Block/Shield Slam when you charge in...

One of them is missing two of them in a row when you charge in.
Or, in my case, forget that DP on CD + Low mana = droolin warrior without moves.

[Jivatma]

Str increases AP and shield block value. I really see no reason to gem str as a tank.

[Insahnity]

It also comes down abit to RNG. There are tanks who stay under the expertise cap and do just fine say... 97% of the time. And out of the 3% they do fail to land a blow, how many of those are in non-critical situations from a threat perspective (i.e. when tank has a massive lead towards the end of the fight)? I believe in never seeing the day when I wipe a 25 man raid because my initial swipe/cleave/etc. fails to land because it is dodged by a few mobs, and being unable to gather all of them up before a few healers and/or DPS are munched, botching the encounter as a whole. Yes, that will be an extremely unlikely event, but then again, it is extremely unlikely that the universe could have been created by a tennis ball sized mass of super-concentrated energy. If you believe that sort of thing, the counter is "it only has to happen once!".

Comparitively speaking, strength for the most part will provide insignificant gains on the initial pull, where threat is more important. Over the long run, strength does provide significant threat improvements, because adding a little extra threat to every hit adds up after a while.

As far as mitigation is concerned for str, most people agree, regardless of talking about SBV for Pallies/Warriors or Parry for DKs, the gains are quite small when you compare to boss encounters where survivability is truly an issue. You would need something like a Hyjal swarm to make the SBV or parry really important.

So back to threat. Do you boot RNG out of your life by stacking expertise, or do you opt for steady gains from AP and SBV? Well it depends on where you are in life. If every encounter ends with you having a huge epeen threat lead, which is typical of lower content and lower tanks, then go for expertise, a bigger epeen doesn't change the outcome. However, if you see DPS consistently riding your ass threatwise, especially at the end of the fight, a little more expertise is not likely to help as much as extra AP/SBV. This example is more typical of high end tanks with similarly geared DPS, and the tanks are likely already smart enough to be expertise soft capped.

[Edgewalker]

Of course you do realize that the parries that occur throughout the fight have just as much of an impact on overall TPS as minimal gains to strength right?
3% chance to be parried is a pretty significant chance if you are maximizing.

[Esch]

Generally, expertise removes a dodge/parry chances by mobs, thus increasing the chance you apply threat. Strength increase the threat once applied. The guideline I heard in BC for DPS was increasing hit 1% (until cap) meant a 1% increase in DPS. Expertise, until 26 skill, gives a 2% increase as it negates both dodge and parry.

Napkin Math: Working from the premise that expertise give 1% increased threat per 16 rating, and threat abilities give double the threat of the damage dealt, how much strength would you need to gem to get a 1% increase in threat.

In other words:
1% Expertise = 2% increase in damage (as you hit more often by negating parries and dodges to 6.5% expertise)
1% increase in damage = 2% increase in threat --> requires how much strength?

Simplification: Magically assume AP increases directly improve threat. In reality, AP is a major portion to increasing weapon/ability damage, but doesn't get applied at 100% to everything.

Since Strength scales 'slower', as you get more and more Attack Power, it doesn't keep pace with the linear increase in threat in Expertise. Applying napkin math, gemming 16 Strength when you have 1000 AP gives you 1032 AP, or 3.20% increase in dps, or 6.4% threat. If you start at 3k AP, 16 Strength leads to only a 1.00% increase in DPS, or 2.00% threat. In other words, the more attack power you stack, the less threat increase you get from Strength, while expertise gives a predictable increase in hitting targets.

Going back to the simplification, if stacking Strength isn't going to keep AP comparable to Expertise, then considering the modifiers to abilities would only make Strength lag farther beind.

Now... did I futz anything in there badly? I think I got the general logic.

[Warloco]

Few things suck more than missing that big Shield Block/Shield Slam when you charge in...

I assure you, Recklessness + Shield Block + Shield Slam sucks even more

[Lenox]

Great answers so far. This whole "gemming for strength" thing has always boggled me. A new-to-80 fury warrior friend just built up a tank set and it was littered with strength / other stat. I told him that expertise outperforms, etc., and gave him many of the same reasons you have all stated, but wanted to go back to him with specific threat numbers. I now see that there really is no need to quantify how much worse strength gemming is for tanking as compared to expertise gemming (especiallyl if under 26).

[Lorina]

In other words:
1% Expertise = 2% increase in damage (as you hit more often by negating parries and dodges to 6.5% expertise)
1% increase in damage = 2% increase in threat --> requires how much strength?

Threat = 2x Damage (generally). But 1% more damage = 1% more threat.
If Damage = 1000, threat = 2000. 100% damage, 100% threat
If Damage = 1100, threat = 2200. 110% damage, 110% threat

It doesn't matter what sort of multiplier you throw on between damage and threat. As long as they're linearly dependent on each other then they'll always change by the same percentage.


The easier argument for the OP might just be to ask a similar question: Should a tank gem for Hit or Crit?
On paper, 1% hit = 1% crit = 1% more dps. But it's pretty obvious that if you can't reliably establish threat (or taunt...) things will go horribly wrong.

You miss the most important value of expertise and hit if you look at them from a purely numerical TPS value. Yes, hitting something 2% more often gives you 2% more damage and threat. But, NOT hitting something for that 2% makes a miss streak that much more likely at a critical time. It's the balance we all try to find between lots of threat and consistent threat.

Ignore hit rating and assume your new lvl 80 tank is well below the expertise soft cap, so he might have about 15% chance to miss the target. At that rate, roughly 1 in 7 swings miss. Translate that to 1 in 7 boss attempts where his opening shield slam misses, and pretty good odds that the next hit won't connect either. Throw in a moderate hit rating, say 5% more chance to miss, and your problem is that much worse- 1 in 5 swings won't connect. That doesn't guarantee a wipe, but it does make it much more likely with trigger happy dps, big heals, or just a tired raid after a long night. At that point it doesn't matter how hard his shield slam hits, I'll send in the tank who can actually hit the boss.

Now your tank has figured out that gemming for strength is dumb, and he's at least soft capped. At the soft cap he's down to 7.5% chance to miss, or only 1 in 13 swings. He might be sad about his less than godly shield slams now, but they'll actually connect when he needs them and they really shouldn't be all that much lower. Healers and DPS don't get one-shot, bosses drop fat loots, and everyone cheers for their suddenly awesome tank.

The balance question comes in when your tank is comfortably above the soft cap and trying to figure out exactly how much expertise is necessary. I wouldn't switch to strength gems at any point, since stam/exp gems will always be a better choice than strength. At this point the balance comes in matching your raid group and making sure you can keep pace with their threat or if you need to boost your health instead for tough encounters.

[ShadowBumble]

I personally think that if your under the Exp cap ( 26 ) you should go for Exp gemming/enchanting ( don't forget the old Bracer enchant !!! ) , but as soon as you hit 26 Exp you should go turn to avoidance stats, i personally currently have the luxurious position i get a lot of my stats pure from my gear and am stacking Pure Stamina ( +20 sta epic gems ).

I currently trying to calculate if it helps if i change all +30 sta gems to exchange them for +dodge/+sta epic ones for more avoidance.

I think it all comes down to personal preferences in my book i will never gem my tank for strenght.

[Mert]

Since you did mention other classes being welcome to respond, I'd just note that for Paladins you get more threat per point of Strength than anything else, even if you're below the hit cap and/or Expertise soft cap. That said, both Hit and Expertise have other benefits that may make them attractive unless you're going purely for highest threat - Hit will make your taunts less likely to miss and Expertise will make it less likely you'll be parry-gibbed.

[Breccia]

I ran the numbers on str, expertise, and hit for warrior tanks a while ago and posted to the DPS forums. You can find the full math behind my results here

http://www.tankspot.com/forums/f177/...x-dps-tps.html

but the short answer is, expertise is better than strength until the "soft cap" and even then it's a close second.

[Insahnity]

Personally, I find that expertise and hit are much like dodge and parry, you can gem for it, but by and large you get most of it from the gear that you do get. Gemming for expertise or strength or hit must be balanced also with gemming for survival. Either you hit your caps and have less than maximized stamina or you stam stack and run greater risk of not holding threat for a variety of reasons (misses/dodges/parries, not enough snap threat because of raw DPS, etc.). Personally I try and go for soft caps at least and then switch to survival worries.

[bacchanal]

Since Strength scales 'slower', as you get more and more Attack Power, it doesn't keep pace with the linear increase in threat in Expertise. Applying napkin math, gemming 16 Strength when you have 1000 AP gives you 1032 AP, or 3.20% increase in dps, or 6.4% threat. If you start at 3k AP, 16 Strength leads to only a 1.00% increase in DPS, or 2.00% threat. In other words, the more attack power you stack, the less threat increase you get from Strength, while expertise gives a predictable increase in hitting targets.

Fallaciouis thinking there for the AP in a number of ways.

First off, a 3.2% increase in AP does NOT increase dps by 3.2%. Considering other factors go into the damage formulae for our damage abilities (weapon damage and shield block value, for two example), it isn't as simple as that. And on top of that, a 1% increase in DPS is not a 2% increase in threat. Besides the fact that some of our threat comes from innate threat values (a flat amount for shield slam, a percentage of AP for devastate, flat value for revenge, etc), even with that taken out of consideration, a 1% increase in DPS would be a 1% increase in threat - example via napkin math:

1,000 damage concussion blow (no innate threat) = 2,073.5 damage worth of threat
2,000 damage concussion blow = 4,147 damage worth of threat

You'll see that that is a 100% increase in damage - and a 100% increase in threat.

I've really been meaning to put together a spreadsheet that can model the basic threat abilities (heroic strike, cleave, shield slam, revenge, devastate, concussion blow, shockwave, thunder clap) based on gear and stats, and will give an exact value for an increase in any given stat - but it may be a little bit before this project gets out there. It's going to start with a comparison of weapon speeds and how they affect threat, and that may be out there soon.

[Dragaan]

For boss tanking, expertise is your best bet until hardcapped (when compared to strength). If you are already at or over 26skill tho, strength is pretty nice because it will help on trash, boss adds, etc. When I go for a threat/dps record on a boss (single-target), my first priority is expertise and hit capping then block value then strength.

[Agmar]

Expertise reduces spike damage. It's the best stat other than stamina, in my opinion.