See:
If your innate headshot is 0%, the ability has a 10% chance to trigger per attack. That’s a 10% chance to trigger on the first, second, third and fourth attack. (and a 34.4% chance of triggering overall)
If your innate headshot is 25%, the ability has a 10% chance to trigger per attack until you get a headshot. That’s about a 25% chance to trigger over four attacks.
If you add a flail and juggle skill to increase it to 40%, the odds decrease of the ability providing a bonus even further. Any stacks you acquire of this ability have a 20% chance to trigger over 4 attacks.
And this isn’t even counting the fact that you’ll be receiving the opportunity to do so less often!
