Anyway, imagine we are playing against a reg.. its much closer than we might thought.. Lets have a look:

His possible flop raising range 99-TT,AQ,AK,KQs.
Turn barreling range: AK,99-TT,KcQc
River barreling range: AK (at best), 99-TT. Vs this range we have got exactly 25%. So yeah, its pretty close (I discounted all bluffs, so if I would add one combo and we might be better off calling, but I counted all combos of AK from which some might 4bet pre, some just call flop, check turn or check river.. )
I also didnt include ATs which should be folded pre, but some guys might call that hand as well.

Btw in this case we do block KcQc so this bluffcatcher isnt best either and QJs,87s or whatever are the other draws.. most of them are just fold preflop, even KQs is more of a fold, but there are some regs who arent able to fold it, but really small portion of them would blast it off, even if it might be the only unpaired hand OTF which they have got.

That said, since the call is heavily dependent on his bluffing range, I would prob call AK without a Kc since I believe they might bluff from time to time which might be enough for us to justify a call since again vs the range AK,99-TT we have 25% equity.. and AK is really the top of our range (but due to MDF and our pretty tight 3bet range preflop, I dont think we are supposed to defend all AK OTR and if so, then its already pretty close + compared with the fact that barely any reg at nl50 is trying to bluff someone of AK here, I think this might be a fold with every AK.. but need some confidence that we are dealing with a reg who is aware of that.. since I believe there is also certain subset of weaker regulars who are blasting off AK all the time like this and might even add some AQ to it.. or those who arent raising the flop with sets..)

Soo my conclusions: folding every AK vs a proven reg without volatility or wrong value betting read and against nits.. calling AK without a club against guys who havent proven reggish identity yet or are inclining to some sort of volatility/fishy plays, calling every AK vs a rec player.