The Spirit Realm

Ok, i know there are tons of threads on this, from what I have gathered, Enhanced Agression, Earthen Strength and Slay undead are the only aa's that will increase slay damage right? I am lvl 85 with the HoT T3 paly only sword, with dmg aug its 194 dmg /36 delay, max slay I am seeing is 33k with shaman buffs.
I have a friend with similar gear, aa's and weapon, doing close to 40k, what am I missing?

Slay is a multiplier so your weapon is the MAIN thing that increases your slay damage. For eye candy you want the biggest damage on the weapon you can get, for DPS you usualy want ratio over Damage.

Enhanced aggression and earthen strength will NOT increase your top damage on slay. They make it more likley that you will do your top damage then a lower damage slay but they will not increase your top damage.

Earthen str = heroic str

10 heroic str = 1 point of damage that is added onto the end of all calculations as a bonus damage. So if you slay for 1000 points of damage and have 10 heroic str your max slay will be 1001. Technically it increases max slay but it does not factor into the base damage to be multiplied by the slay multiplier. It is mostly useless.

Edit to add* I may be wrong on the heroic str part - if so you can ignore this. I'll ask around to confirm.

They're not heroic.

They just raise the maximum that a stat can be raised by items or spells by 5 pints per rank.

I'll elaborate a bit on what I meant. Heroic Strength raises the cap, which means more Strength that is usable. Given that there are two immutable components for melee damage: strength and skill rating, they definitely affect the damage amounts and sit at the core of the algorithm.

You can see the evidence of this in game by parsing out your damage table. Go out to some constant undead, meaning there is little to no differences in individual mob levels and only one type present. Fight against them for a couple hours with only simple buffs that affect your HP/AC, regen, and attack speed (don't contaminate the parse with stat buffs). Run through with a parser that can separate damage amounts, or do it by hand in notepad (think I used Yalp, maybe it was another similar parser). You should find 20 unique normal damage amounts, 20 unique critical damage amounts, and 20 unique slay damage amounts. After finding the lowest common denominator in each group (normal, critical, and slay) then applying it to reduce them, you should find those tables are identical. The denominator in each group is the multiplier being applied to your damage table. Increasing your strength raises those values in the table but it does not raise the multiplier, this is significant because if the multiplier is 2 (just as example) a change of 1 becomes a change of 2 in the final value.

Now back when I worked at that stuff, I was woefully bored. It was during DoD with those mobs that like to CH themselves endlessly, so the parses I took were very consistent since I could blindly swing my sword for hours on end and not kill one. Against varied mobs you would have to allow for variances in damage amount, which could take a lot of extra work to group up (the numbers in one group are spread somewhat evenly from minimum to maximum).

Never really got into doing this for all level ranges, it was time consuming enough doing it for a single level. But I suspect the damage table is uniform across every level and likely every class, with only a difference of addition/multiplication. Would not surprise me at all to hear it's a static array that's been in the game's code base since weapons were introduced with a programmer macro that takes index, offset, and multiplier as it's parameters.

Regardless to what the exact formula is, I highly doubt that the stat cap increasers are going to account for a 7k difference in max slay. You say similar gear, but that really isn't precise enough. I would suspect that if you are using 1handers (you and the friend you are comparing to), then perhaps you are missing the Shield Specialist AA's maybe? Those will make a very big difference in 1h slays.

The single biggest reason for difference in max slay amounts is weapon damage. (outside of the obvious, like having slay AA's maxed) Other possible things that will skew numbers include Righteous Indignation slays (which you cannot pick out from normal swings if you happen to use a slash weapon for your DPS modes), the kill shot AA buff running, certain aura effects/epic clicks, glyphs, maybe a few other odds and ends.

Is it possible you are not looking at a large enough sample data? You mention a weapon stacked to be 196 damage and getting 33k slays out of it. My 1hander is 156 damage, no damage aug in it at all, and I still routinely see 32-33k slays with it. /shrug, that's about all I can think of to look at.