did i misplay or just badbeaten?

This one's been bugging me for awhile. I've been over and over it and it's still bothering me. Did I misplay this or not?

Was in a 75-player freeroll with $10K in prizes going to the top 50. Clearly they expected a bigger turnout.

In any case, starting BR was $1000 with blinds doubling every 10 minutes. In the third round (25/50) I was dealt AsAd in middle position and raised to 150. I was just transferred to this table so didn't have a read on it. I had about 1200 and only the BB called with about 2500.

Flop came 5s 5c 8s. BB bet 100 into a 350 pot. With a bet that small I figured he either had a PP smaller than me but larger than 8 or that he figured the flop missed me and would pick up the pot. I knew that if I raised he was gone so I figured I'd let him hang around one more street. I wasn't too concerned about another spade since I had the A (prolly not smart in hindsight).

Turn: 9s. BB bet 150 into a 550 pot. Damn. I hadn't considered that he might have something like JsTs in which case he'd just hit his flush. I still had outs in any case and still might be the best so I resolved to just call him down.

River: Qc. A blank as far as I was concerned. BB bet 200 into an 850 pot. I called and he turned over JcTc for a runner-runner straight. I was a 90% fave on the flop and a 87% fave on the turn. WTF!?!

I keep thinking I didn't misplay it but if I had known what he had then I totally misplayed it. Help put this demon to rest!

Were you just calling his bets? I think on the flop you should raise him the pot and see what he does. Make it more expensive for him and don't let him think he's in control.

I might lean to a misplay and I have made this mistake before of stringing guy along only to see them catch. I would have reraised with a pot sized bet or pushed all in. Hard lesson to learn.

[PFrese]

Knee jerk reaction is to say you played it wrong and should have raised the flop, but I also make plays like this, when I have a strong hand and want to get more action. Then you get the scare card on the turn.... So, I can see why and how you got yourself into this spot.

BUT, in reality, you should have raised the flop up to 500 or so to better define your hand. But, if he pushes, what do you do? He knows you do not have a 5. Tough hand...

I want to see how the guys who are much better than me say to play this hand.

I'm thinking now the deciding factor to raise on the flop was the size of the pot. With the BB's bet, it was up to 450 so a raise would net me 300 if he folded, a 25% increase of my stack.

So here's a follow-up question that I hope won't need it's own post to get answered: when is a pot "big enough" to protect?

[reecelights]

On the flop he looks to be protecting his Broadway cards (possibly spades) or his 66 or 77. He doesn't have an 8, a pair bigger than an 8 or he would be more aggressive. He doesn't have a 5 (wouldn't call PF or would check here). His bet is small and is probably just buying him time to catch up. You may or may not want to raise here, but should plan on taking the pot down on the turn. I lean towards (especially in the early going) pushing out draws and being satisfied with increasing my stack 25%.

Turn: He is now open-ended. If he hit the flush he would have bet at least half the pot. If you had bet 150 into a 550 pot he would be getting correct pot odds to call (4.67-1). You have to raise the turn. There is 700 in the pot: push and be happy.

Thank you. I totally agree.