AJs in SB vs. unknown UTG raise

[wdcbooks]

I would usually raise 66 UTG. I would also have three bet AJs. You gain so much information form your opponent's reaction to a three bet that it is worth it, even if you don't think you have the best hand.

If he caps you can play the hand outa little more passively, afraid of the overpair. If he just calls you usually don't have to fear the overpair and you are much more likely to be ahead here.

That is of course unless he has 66, then you're screwed.