[olavfo]

Is SB one of those who play tight, but can't lay down KK-JJ when an ace flops? He doesn't seem to like his hand very much at this point, yet, he doesn't fold. A big pair is a possibility, or he could be on a flushdraw (would he raise KQs, KJs preflop?)

When SB checks the flop he could be going for a check-raise, but if he had an ace wouldn't it be obvious to bet it? I would call to see what happens.

When the board pairs we have a good chance of chopping with BB (not to mention BB could be semibluffing with a draw), and I would call down and hope SB keeps overcalling. If a big pair is what he has, he is making a mistake, and I want him to make it so I don't raise. Those times he is on a flush draw we should raise, but since raising won't protect our hand against a flushdraw anyway, and since SB's tightness makes a big pair more likely than a draw (or at least that's what I think), I just call.

If it's checked to me on the river, I bet. If a third spade falls and there's a bet in front of me I have to think long and hard.