It's around 45-50% from my testing. When I get the chance I'm going to run a larger test.... it just sucks to run since you need to attack slow enough to discern when you OAT procs. I'm still only at the Lv85 stage, since ZNM is a huge timesink, and they've eluded to possibly revamping the system. (I don't mind waiting a few months for the next major update if it makes ZNM easier.)
