I was at first hesitant to ask this question, but I did see a related (yet much older) one here in meta: Is there a bug with Strunk & White badge or am I not understanding it?. However, if I turn out to be wrong and this is incorrect or lame, I'm not above deleting this question.
I earned the "Tenacious" badge. I believe that I have enough zero score answers to have also earned the "Unsung Hero" badge, but that one is not showing. I thought it may be that there's a time period (waiting to see if someone votes or changes the accepted answer, etc), but that doesn't seem to be the case. So just trying to understand why.
I have 27 accepted answers, 12 are zero score answers. That's more than 10 and 25% of the total.
Is the calculation inclusive of all answers (including non-accepted answers)? If so, I have 64 total answers (including not-accepted answers). Could that be it?