My very first post here! A really great site you've got... Well, I'll cut to the case. A $100NL hand from William Hill, I'm Oyvindg in seat 3:

Game #425104464: Texas Hold'em No Limit ($0.50/$1) - 2005/05/01 - 15:53:19 (UK)
Table "Jacinta" Seat 5 is the button.
Seat 1: shay313 ($27 in chips)
Seat 2: Nokke ($45 in chips)
Seat 3: Oyvindg ($120.50 in chips)
Seat 4: MAG1C1AN ($89 in chips)
Seat 5: LarsruneY ($93 in chips)
Seat 6: Frjack ($141.75 in chips)
Seat 7: Mr.Maniac ($237 in chips)
Seat 8: BennoOnl ($110 in chips)
Seat 9: redsox05 ($51.25 in chips)
Seat 10: The_Rep ($33.50 in chips)
Frjack: posts small blind $0.50
Mr.Maniac: posts big blind $1
----- HOLE CARDS -----
dealt to Oyvindg [Ac Kh]
BennoOnl: calls $1
redsox05: folds
The_Rep: folds
shay313: folds
Nokke: folds
Oyvindg: raises to $4
MAG1C1AN: folds
LarsruneY: folds
Frjack: calls $3.50
Mr.Maniac: folds
BennoOnl: calls $3
----- FLOP ----- [8s Jc Ad]
Frjack: checks
BennoOnl: checks
Oyvindg: bets $6
Frjack: calls $6
BennoOnl: folds
----- TURN ----- [8s Jc Ad][3h]
Frjack: bets $15
Oyvindg: calls $15
----- RIVER ----- [8s Jc Ad 3h][Jh]
Frjack: checks
Oyvindg: checks
----- SHOW DOWN -----
Frjack: shows [Ah 9h] (Two Pairs, Aces and Jacks, Nine high)
Oyvindg: shows [Ac Kh] (Two Pairs, Aces and Jacks, King high)
Oyvindg collected $52.25 from Main pot


I just have a very thin read that tells me he is quite Loose and passive post flop.

Comments on all streets, especially my possibly(very possibly that is) weak check on the river.

Once the J hits on the river, I bet into him, what scares me on the turn is a pssive player betting to me, usualy means stregnth and I am now really afraid of A3 or A8, after he checks the river, I think that is even more likely, it is rare to get check raise on the river, so I bet here, if he has AJ and raises that sucks but you were beat anyways.

I don't think he has AJ cause he didn't bet out the flop, which most people do w/ 2 pr. Plus, who checks the river w/ a boat...? He was playing a little more like trips, but when he checked the river, you had to know he didn't have it... His only holding that scares you is A3, and the river took that away from him. I probably would have bet more on the flop (closer to the pot ~$10), and definitely bet the river... I seriously doubt he's slowplaying it... At best he has 2 pair w/A3, and the river was a perfect hit for you, and nullified his 3...