3b pot vs jesse sylvia
Hey all. Hand happened yesterday at the bellagio 5/10.

Villain: Jesse Sylvia. I remember him from the ME a few years back but don't really know his cash game background. We've played a few pots thru the night. Notably I opened from CO and he peeled BB. I checked back a K89r flop with plan to delay cbet and he lead 4r turn for potsize. Pretty sure he doesn't think I'm protecting my flop checkback ranges.

Hero: Average 5/10 grinder.

$1500 effective
MP limps
Hero opens HJ to 40 with Ac4c
Fish calls from CO
Villain 3bs to 160 from SB, MP folds, Hero calls, fish folds

Pot 380
Flop As5c6s
Check check

I think I might have made a mistake here by checking flop but not sure. His small squeeze made me think he is merging his 3bs and playing all continues as a raise and will have A2s-A5s, ATs+ in his range here. So I went with checkback.

Turn Qc
Villain bets 260, Hero calls

Pot 900
River 2d
Villain bets 850
Hero?

His large sizing on river definitely seemed like he wanted to make it look polarized. If his range is polarized to AA/QQ for value + bluffs I have to call obviously. But given the action it really felt like he was merging and might have AJ/AT in his range. I also don't know if higher stakes players will turn JJ/TT into bluffs here since they block my best calling hands. Or whether or not he plays AK/AQ like this maybe 10% of the time as a mix. I don't see this line very often at 5/10 so I'm having a hard time working out his range.

Thoughts?