Edit: Editing this to note that this original claim/assertion has since been proven false. Read the thread if you want to know what was going on, but don't take it as a valid state of how things work.
So, there's some unsettling new revelations regarding the relationship between DA and TA coming out in a thread over
in this thread, starting about this post. Data appears pretty solid, though more generalized testing is likely to continue.
Caveat: Whether this is a bug (and thus may potentially be fixed) or intentional (and thus remain as it is) is completely unknown at this point.
Executive summary: In calculating your overall chances to proc either DA or TA, in the event that they both proc, *neither* takes effect.
In other words, there is no priority of DA over TA, or TA over DA. The calculations for both of them puts them in the 'under' category.
This has a measurable effect on anyone using Apoc atma, but will have the greatest impact on thf gear choices due to the high TA rate they can achieve.
The math for figuring out the 'actual' DA or TA rate based on 'listed' rates is:
DA = (1 - TA%) * DA%
TA = (1 - DA%) * TA%
It's unknown how quad-attack mixes in with the above. It's also unknown how this may interact with OAT/OA2-3/etc weapons.
So, how much of an impact? Let's consider a fairly high TA thf:
Triple attack
-------------
Base + merits: 10%
Apoc atma: 15%
Triplus offhand: 3%
+2 head: 3%
Epona's Ring: 3%
Total: 34%
Double attack
-------------
Epona's Ring: 3%
Atheling Mantle: 3%
Twilight Belt: 2%
Total: 8%
Suppa for one earring, the other slot left empty.
Total additional attacks per round:
Base: 0.6784
w/Brutal Earring: 0.6774
w/Raider Earring: 0.696
In other words, not only is the Raider's Earring better than Brutal, adding the Brutal Earring actually reduces your hits per round below the -base- level. Raider's, on the other hand, gives about a 1% gain in overall damage (excluding SA/TA).
So, how much TA is necessary for Raider's to beat Brutal?
Going to assume 8% base from the other three items, but will also look at 5% (removing Atheling Mantle)
(TA+1%) * 92% * 2 + 8% * (1-(TA+1%)) = TA * 87% * 2 + 13% * (1-TA)
(.92TA + .0092) * 2 + (.08 - .08TA + 0.0008) = .87TA * 2 + .13 - .13TA
1.84TA + 0.0184 + .08 - .08TA + .0008 = 1.74TA + .13 - .13TA
1.76TA + 0.0992 = 1.61TA + .13
0.15TA = 0.0308
TA = 0.2053
So at 21% and higher total TA, Raider's Earring matches or beats Brutal (not counting the Store TP).
If you remove the Atheling Mantle (using Cavaros or whatever), the threshold is:
(TA+1%) * 95% * 2 + 5% * (1-(TA+1%)) = TA * 90% * 2 + 10% * (1-TA)
(.95TA + .0095) * 2 + (.05 - .05TA + 0.0005) = .90TA * 2 + .10 - .10TA
1.9TA + 0.019 + .05 - .05TA + .0005 = 1.8TA + .1 - .1TA
1.85TA + 0.0695 = 1.7TA + .10
0.15TA = 0.0305
TA = 0.2033
Still the same: 21% or higher.
What if you have no other DA gear at all?
(TA+1%) * 100% * 2 + 0% * (1-(TA+1%)) = TA * 95% * 2 + 5% * (1-TA)
(TA + .01) * 2 = .95TA * 2 + .05 - .05TA
2TA + 0.02 = 1.85TA + .05
0.15TA = 0.03
TA = 0.20
20% TA is when the two earrings are equal (so outside Abyssea Brutal still wins, since you can only really get a max of about 20% from trait/merits/gear).
On the other hand, that 21% threshold means that as soon as you equip Apoc atma, Raider's beats Brutal, regardless of other gear.
And what about the other direction? Adding /war for 10% DA:
(TA+1%) * 85% * 2 + 15% * (1-(TA+1%)) = TA * 80% * 2 + 20% * (1-TA)
(.85TA + .0085) * 2 + (.15 - .15TA + 0.0015) = .80TA * 2 + .20 - .20TA
1.7TA + 0.017 + .15 - .15TA + .0015 = 1.6TA + .2 - .2TA
1.55TA + 0.1685 = 1.4TA + .20
0.15TA = 0.0315
TA = 0.21
And max lucky Fighter's Roll for another 24%:
(TA+1%) * 61% * 2 + 39% * (1-(TA+1%)) = TA * 56% * 2 + 44% * (1-TA)
(.61TA + .0061) * 2 + (.39 - .39TA + 0.0039) = .56TA * 2 + .44 - .44TA
1.22TA + 0.0122 + .39 - .39TA + .0039 = 1.12TA + .44 - .44TA
0.83TA + 0.4061 = 0.68TA + .44
0.15TA = 0.0339
TA = 0.226
With extreme amounts of DA devaluing TA, you'd need 23% TA for the Raider's to win. Still basically as soon as you equip Apoc atma.
Also, with the prior assumption of TA priority over DA, there was no consideration given to DA hurting the impact of the Raider set bonus. Since DA values hinder TA, they also reduce the (admittedly limited) benefit of the AF3+2 set.
Of course I just tossed a Raider's Earring last week since I thought it wouldn't do me any good. Have to get another...
Edited, May 11th 2011 10:14am by Kinematics