Hey, first hand i actually post here. Start off with a bad one :P

So Villain seems to be Regular,plays 20/17 in 300 hands.
Preflop standart i guess, on flop I bet all of my range on this board. Villain probably calls some suited broadways with BDFD, his Ax, middlish Pocketpairs and probably even all his sets (33+66 and if he sometimes has it his AA as well)
Turn i check, actually dont know why, dont like it, think AK can go for 3 streets and doesnt really need to pot controll, even out of position.
On river I go for value about 2/3 pot and get raised, since he didnt bet the turn, i dont think he has a set nor a two pair, since they probably also all bet turn. So his value hands should be 99 and maybe A9s, and sometimes of course he has some sets anyways that he decides to check back on turn. What can he be bluffing with? small pocket pairs? missed broadways that didnt hit at all? Even if I put him on JJ, 99, 66, 33, A9s, AK and give him some bluffs like 88,77, KhTh, KsTs, KhQh, KsQs, i still have 54% Equity but only need 33% to call. I my opinion theire defenetly underbluffing here, so i still like the fold on the river.
Other opinions highly appreciated :P