PLO50 QT97ss river line?

A) would tend to bet 33% because i would perceive he has a pretty weak range
B) i think the information is somewhat unprecise.
f.e. you maybe have some history and he just barrels into you even he got caught regularly. or versus a bet by you, he won't even raise nuttish hands because you have a tight image, etc. so something like a inducing blocker bet could maybe be useless or could otherwise work pretty well if he blindly would attack those.
just with the pure assumption, he might tend to over frequently bet the river i would try to get a bet by him and check.

I were thinking if he has hand like Kx or 9x or similar he will just check if I check. Of course there are also fair amount of busted draws that could bluff versus check. But my idea was that if I bet smallish he might attack that because he will have way more KK, 99 and maybe also K7 in his range. Though he might also have those decent amount of time even if I block them. So in game I bet 4€ on river and villain raised to 17€ or so. Which I then called. But versus unknown I might either x-c or lean toward bet-fold.

yepp, it depends. if you dont have a super tight image then leading small frequently could be a nice option too.
versus unknown, i think especially if they have like weird stack size, i think they are often just pretty weak here and would like to bet frequently as well

I think I could also bet bigger side here, polarizing more to FH or missed draw which this board and flop has tons of. I dont think it's unheard of to get herocalled this run-out wider.

And vs raise in that case it's easy fold if thinking villain is ubcapable of big bluffs. Vs aggro bluffer type nice spot for him to bluff Kx and you to call

Worked nicely versus this guy as he had AKT3 kind of hand.

Vs unknown bet, vs aggro check-call. EZ game.