2 pair is harder to assume when no pair is on the board, and this type is the one most likely to beat us. After the flop the villain is definitely not folding top two pair. A straight is unlikely for him too as he would have had to be confortable calling your bets with a 3-5 hand Even if he had a J6, he would still be confortable betting into you top pair with the other card locked up in a pair. AA, JJ, JT, TT J6, T6, J4, T4, J2 and T2 are all good against pocket pairs and random Jacks or 10's. He might call with AJ, QQ, but I don't know if he would lead betting with them. Your bet sizing is a little smallish preflop, and quite small opening after the flop generally, but if you were attempting a slow play and keep the villian in longer it makes sense. You have great pot odds for every street you played, so it makes sense to call the river. However on the turn bet you did 70%, which is enough to cause many hnads to fold and the villian did not. He must percieve he has a made hand. Your decision to check the river seems okay if you trying to see if he had a hand good enough to lead the betting with, and then you fold, which he did, but you called. AA, a set of J or T, or 2 pair is what I expect if he leads on the river. The 3-5 is highly unlikely. Of course the villain could be a noob and is pushing with a random J, but we don't know that. I've had a top pair beaten many times this way (either to a 2 pair or a slow played set) that I am wary now with top pairs. All of that being said, KK wins enough of the time, and at no street was you odds bad, so you play is good here statistically. Situationally though, I would fold at the £14 bet. He has something, he called a pretty high bet and then led once he had the chance. Maybe a higher preflop bet of 4X or 5X would have him fold, but nothing you could have done post-flop was getting a fold from him. Your bets strategy then is to see whether or not you are beat. Your Turn strategy plus the check the river together followed by his lead bet was enough information. However if that was your strategy, it might be best to raise higher immediately post-flop, then check the turn. You'll find this information out sooner. For example if you had raised £5 after the flop, and he called a bet that size he has something. Then check the turn, and he leads then instead of at the river. You could fold at the turn with a smaller loss. If he checked, then you lead on the river, probably still losing less bezause you attempted to get information from him. Best to bet bigger earlier and get the info at the turn.