
Originally Posted by
Kitru
Fracture is a 300 potency hit that you can throw out once every 13 GCDs (12 GCDs for the DoT duration w/o breaking combos and 1 GCD for itself). Considering the average potency/GCD from special attacks of most of those attack strings is ~200, assuming you're not messing with Maim/SE debuff uptime, you're getting an extra 100 potency every 13 GCDs, which is 7.69 potency/GCD. Assuming a baseline potency/GCD of ~370 (SP>SE>BB, which is the median), that's a 2.08% increase in DPS (it's actually lower than this because using it would interfere with Maim and SE debuff).
The problem with Fracture, however, is that it is expensive. The WAR combos all consume 63.33 TP/GCD ((70 + 60 + 60) / 3). As such, throwing in Fracture every 13 GCDs equates to a cost of 64.61 TP/GCD ((63.33 * 12 + 80) / 13), which is a 2.02% increase in TP cost.
As such, in any TP constrained scenario (any prolonged fight without regular periods of doing nothing, e.g. Titan HM and EX, coil), Fracture doesn't really do anything and, in fact, will end up reducing your damage by stopping you from reapplying Maim/SE when you're TP starved. If TP isn't a consideration at all, it's a tiny DPS increase that you probably wouldn't notice.
You actually don't want to use Berserk on CD because it ends up contributing less over time than if you only use it once every 120 seconds while you've got Unchained. The reason for this is pretty simple: the 33% damage increase from Unchained balances out the loss of contribution from artificially increasing the CD by 33% (90->120) but it also reduces the loss in damage from the Pacification effect from it by 33% for the same reason.
If you've got IR, you want to use Unchained>Berserk>IR in that order whenever you've got Unchained up and use IR on CD otherwise (it's a 60 sec CD compared to Unchained's 120).