This is more or less a standard cooler I guess. Opponent stats over 33 hands: VP 53 / PR 6.
I think the objective on the flop is to get all the money in. In retrospect, I think I should've shoved on turn instead of calling. My rationale in the heat of the moment was to let the opponent hang himself by keeping on betting, but the range where I can see him stacking are a straight, lower set, 2 pairs or flush draw with As (I have the Ks). If river blanks, flush draw will not pay. All other hands will go all-in anyway.
Seeing as how the opponent is very passive according to the stats (albeit a very miniscule sample size), I knew he had something. However, given that he appears to be a recreational player, I did not put a high probability on him having the nuts. Even if I knew, the correct play is here to stack off.
PokerStars - $0.02 NL FAST (6 max) - Holdem - 6 players
Hand converted by PokerTracker 4
BTN: 105 BB
SB: 137.5 BB
BB: 100 BB
Hero (UTG): 234 BB
MP: 126.5 BB
CO: 283 BB
SB posts SB 0.5 BB, BB posts BB 1 BB
Pre Flop: (pot: 1.5 BB) Hero has K♥ K♠
Hero raises to 2.5 BB, fold, fold, fold, SB calls 2 BB, BB calls 1.5 BB
Flop: (7.5 BB, 3 players) Q♠ 9♠ K♦
SB bets 3.5 BB, fold, Hero raises to 12 BB, SB calls 8.5 BB
Turn: (31.5 BB, 2 players) 5♥
SB bets 15.5 BB, Hero calls 15.5 BB
River: (62.5 BB, 2 players) 6♥
SB bets 107.5 BB and is all-in, Hero calls 107.5 BB
Spoiler
SB wins 265.5 BB