We have discovered a potential issue with mastery and flametongue weapon and how it affects damage with no mastery rating on gear vs damage with mastery on gear. It seems that instead of a 20% fire damage boost from the base 8 mastery we are getting 2% (yes TWO percent) fire damage boost.
I suspect what we need is beta data on zero mastery rating for only Flametongue damage on both MH & OH, to check to see if its hand specific. Then with identical other stats and only changing mastery (eg: via mastery gem vs empty socket) repeat the tests. If you needed to go back to first test to check anything you could do that with replacing the mastery gem with a stamina one to remain dps stats neutral during the two tests. We are interested in the actual damage done per strike. If this sort of test can be done with different levels of mastery again ideally with NO change in any other dps stat (stamina gems vs mastery gems can achieve this) we might have a better set of data to get our minds working on a formulae.
Simple white damage only tests should be sufficient I think, we also don't want specials or procs to interfere, so ideally test with no proc based trinkets that might change the FT damage. Also DO NOT use any abilities we are testing flametongue damage here NOT SS, LL, searing totem etc etc. The idea is NOT to show off your dps but very very specifically to see what effect changing mastery has on flametongue damage. The test could be invalid if you have more spellpower or more haste or more crit between tests unless you specifically record what values you had at what time in the combat log.
To be valid tests it really needs to be a dummy or mobs that heal themselves where you can be fairly sure that others aren't putting debuffs on the target. eg: most target dummies you find others there and you get all sorts of buffs/debuffs from other classes changing your data. If that happens the test is invalid.
We will need a combatlog of the results to analyse please. Type /combatlog to turn on logging and /combatlog to turn it off.
What might be ideal if you can't find a quiet target dummy is using low level white weapons and hitting on the treants on the ground below dalaran as they heal up themselves indefinitely as long as your dps isn't to high that it kills them.
What we need as results is the mastery rating for each test, the weapon speeds for each test MH & OH, and your spellpower BEFORE you add the flametongue imbues. We also need the combat log so we can check that the test was valid (ie: no special buffs gained that skew the results.)
The more valid test results we get the stronger the case we have to convince Blizzard that there is a bug here and we aren't getting the full buff from our mastery. So please get testing.