http://forum.square-enix.com/ffxiv/t...=1#post3278797
There's also a chart in the OP, I assume it's still valid:
Popping it before CT would be better, at least for me it usually comes off cd between CT-4th, so I hold it and pop between 4th-Phleb, which according to Dervy's math is the optimal place at that point in timeQuote:
In this chart, we can see all of the optimal places to use Blood for Blood. In order of highest PPS, you should use BFB before this skill:
1) Vorpal Thrust
2) Impulse Drive
3) Disembowel
4) Full Thrust
5) Chaos Thrust
