Against KK+, KK is a 23% underdog. Against KK+ and AK+, KK is a 47% underdog. Against QQ+ and AK+, KK is a 57% favorite but this is really a best case scenario against most villains when deep

Correct me if I am wrong, but it's only 1 in 25 times that KK faces AA at a table of 10. Hero's 3-bet represents JJ+ or AK. Most of the time vilian is holding QQ+ or a semi-bluff with AK. If he turns up AA, that's poker. I am with Harrington here that, given the vast majority of players are overconfident in their reads of AA, it is always wrong to fold KK preflop.

In my exp, once you get into 4 & 5 bets, the chances you are facing aces goes way up. Way way up. I have been AI with KK after a PF raising war when my read said "fold, he has aces". Guess what he had? Aces. I have folded KK once PF while 200+ BBs deep. Action at 2-5 went EP raise, someone 3 bets to 55, I just call because I know a 4-bet means AA or KK and I don't want to blow everyone out. Gets around to older gent who hasn't played a hand in a while and he makes it 300. What does he have I wonder? Original raiser calls. I tank for a while cuz I've never folded kings, but I just don't think they're good. I muck. Original raiser has QQ. Older gent has AA. Good fold. Flop comes 7 5 K and I'm reminded how much I love poker.