I've been swapping back and forth between my 2her and my polearm characters. From this I've decided to redo my 2hers stats when he retires to drop throwing for x-bow for more skill point conversions and such. Anyways, what I've noticed is that the polearm "stun" really only seems to happen with a select list of weapons, or perhaps I need more than 18 str or 21 agi to make it happen more consistantly. When I get in fights with such people as goretooth, dexxt, rhuell, john, Man, and so forth I'm not really noticing any noticable polearm stun with the fister or long awlpike, but using an iron staff, long hafted blade or spear I notice it alot more.
Is there some numerical data that influences when, if and how often this effect occurs? Is it anything we can measure and run tests on?