PS $22 - 1st hand: call off all of my chips on the river?

[jd2b2006]

[ QUOTE ]
A couple questions:

What did you put him on after he called your flop and turn bet?
Is A9 that unlikely a hand for YOU to have?



[/ QUOTE ]

After the check/call on the flop, I put him on two overcards. After the check/call on the turn, I thought he might have hit his straight draw from the flop, or is just a HUGE fish trying to hit an overcard. Had he checked the river, I would have checked behind. Since this is a $22 SNG, I do not think my opponent was thinking on a level of "since I hit my straight and a scare card came on the river, if I go all-in he will think I am bluffing and will call with a worse hand." Then again, I have a tendency not to think very highly of my opponent's postflop play at the $20s unless proven otherwise.