Re: NL25 - AK hits vs unknown
 

The size of the bet made me think that he was more likely to buy a cheap showdown. 18 VPIP players very rarely have a 2 in their hand here, and I doubt he ever has 2 pair. The only hands I'm worried about are 44 and 55. If you raise and he comes over the top, it becomes an easy fold.

I guess I could be wrong, though, because if he's not calling both a turn raise and river bet with his Ax hands, then a flat could be better. I see where you're coming from.

Re: NL25 - AK hits vs unknown
 

22/33/44/55 are all in his BB calling range PF, and any of the weaker aces might be if he feels OP has been making blind steals with marginal hands.

Again, we could still be ahead here, but if we raise the turn bet we're only getting called by hands that beat us and folding out the rest. There's more value in seeing the river card and letting him make another small bluff.