Hero is unknown reg.
I have recently played this hand and and i wasn't quite sure about the river play. I probably bet heart FD's OTT and don't have AK or AQ, so any Ax basically is on the top of my range. But when you look at board, it is practically impossible for villain not to have an ace here (don't ever expect him to turn 9x or 88 into a bluff). In game, he did bet very fast, which seems like AK to me, so i just folded. I also realize, that i cannot fold every Ax OTR, i would be overbluffing this spot. But when he did bet so fast, i think exploitable fold based on timing might be a good play.