Preflop fine vs unknown.

I'm not sure how often KK checks the flop either. There's a couple of straight draws, but not that wet.
88 may often check to 'let you hit something'. I don't see AK 3betting you on river so this basically looks like 88, quads or nothing.
I mean it's a bit weird isn't it? We block AA and KK, we have TPTK. There's no draws that have be completed so he's repping a full house and that only. Again AA in some cases. There's also the random case of he reps the K with 33 and spikes river hah.

I think you're trying to get value from KQ, KJ's etc on the river. The only thing is, his bet sizing on river doesn't look like that sort of hand. So you can just call.
Why has he gone close to pot? Is the question all of a sudden.

Just call and take a note vs unknown.

Thanks for your reply. Yeah normally I just would c/c and not c/r that river. But on NL5 Zoom they arent capable of 3b river as a bluff.

I agree with Grocker, this spot is a call. He either hit big on the flop and decided to let you catch up, or he whiffed with overs like AJ-AK. I think a hand like 99-JJ is betting here for value and protection on the flop.

On the turn he bet slightly more than 1/2-pot - I'd call turn there. On the river I'd call even though I wouldn't like it too much and hope we had the best hand. Afterwards, I'd take a note on his actions and sizings.

Sure, but this doesn't really change that fact that your average NL5 UTG opener won't have many hands in his range that you can c/r river for value. I also agree that it should be a call.

Depends on the player. I think a player will find it hard to fold KQ or KJ here. Pretty unliekly he has a fh or set until he re-raises so I like the way we played it.