Another cross post from the official forums.

There are some issues with combat mastery tuning that are causing a number of problematic tuning issues with the spec.

First SimC results: https://www.dropbox.com/s/rhxwuppixnal30u/combat_weapon_final.html?dl=0

This shows three different combat weapon configurations, MH dagger, OH sword, double swords and MH sword, OH dagger.  All use the ilvl 660 pvp set with mastery enchants except slow_fast_haste_stack which uses haste enchants.  Fast_slow_RvS_maintain uses RvS only for debuff maintenance, all others use RvS as primary cp builder during deep insight.

As additional confirmation that this is not an artifact of SimC Vigilate tested Slow/Slow and Fast/Slow with 660 pvp gear and 680 tier gear.  This shows Fast/Slow ~5.6% ahead of Slow/Slow which is consistent with the SimC results.

Slow/Slow: http://www.warcraftlogs.com/reports/86RcgqJbyrZGBN3X/#type=summary&boss=-3&graph=true&start=0&end=718563
Fast/Slow: http://www.warcraftlogs.com/reports/86RcgqJbyrZGBN3X/#type=damage-done&start=921584&end=1675430

There are a few problems with this:

  1. Fast/Slow is a very counterintuitive, I don’t believe that fast/slow has ever been the optimal weapon configuration for combat, and dagger main hands haven’t been a thing since combat daggers was killed in early wrath.  Beyond the historical rationale it just doesn’t make a ton of sense for the weapon that is hitting with spamable abilities like SS and RvS to be weaker than the one that is just there for auto attacks and mastery procs and has a 50% damage penalty attached.
  2. Even in the Slow/Slow setup the OH_dps is more valuable than MH_dps, this is problematic for the same reasons as above, the OH weapon being more valuable doesn’t make much sense.
  3. Combat passive damage (defined as auto attack, poison and MG damage) is very high.  In the fast/slow case it is 71.4% and even in the slow/fast case which should move more damage into active sources still has 63.4% passive damage.  I don’t think we have ever been told the target passive damage percentage however using the other two specs for comparison sub has 38.5% and mut has 34.6% in the ilvl 660 pvp gear.
  4. Despite SS being higher DPE and CPPE than RvS, RvS still appears optimal to use during deep insight (T17 2pc may change this).  Personally I don’t mind that however given that changes were made to prevent this a few build’s ago this is likely a problem.

The root of all of these issues is combat’s mastery is overtuned.  At 225% OH weapon damage an MG proc out damages a sinister strike (100% MH weapon damage) given equal weapons.  While this isn’t strictly tuning related having our main CP builder deal the same damage as a MH auto attack and RvS deal less damage than a MH auto attack seems very problematic.

Shadowboy did a useful analysis of this issue with slow/slow vs. slow/fast (before fast/slow was discovered to be comparable dps) and proposed a revised tuning that moves damage from MG into SS and RvS that appears to solve all of the issues above.  He proposes nerf MG to 140% weapon damage, buff SS to 160% weapon damage and buff RvS to 120% weapon damage.

Full post on his proposal with SimC results demonstrating its effect: http://venomousthoughts.wordpress.com/2014/09/09/combat-off-hand-in-warlords-and-the-problem-with-main-gauche/