Sorry I don’t have the exact HH for this, but it was from early in a nightly $129 bounty tournament on Ultimate Bet. Effective stacks were about 3000, with blinds 15/30.
The UTG player opened with a pot-sized raise to 105. The action folded to me in the BB, and I called with 22.
The flop came 774 rainbow, and we both checked. There is some chance that my opponent is slow-playing an overpair here, but it’s far more likely he has something like AK.
Betting the 9 turn would certainly be justifiable, but I decided to check again and see what my opponent did. Most people who check AK on this flop are going to check a safe turn as well, and indeed this is what my opponent did.
A 5 came on the river, and now I bet 195 into a pot of 225. My opponent called with AQ.
The sense I get is that many people don’t bet a small pair looking to get value from Ace-high, not because they doubt that their pair is good, but because they doubt that their opponent will call. The thing is that after this action on this board, any pair is going to be the best hand 95% of the time. There is just very little downside to betting, no matter how often your opponent folds, because you are so rarely betting into a beter hand.
The other thing that’s important is the size of the bet. Many players, when they do bet, might bet something small, no more than 90. But that bet looks like a value bet, which may induce some opponents to fold. And even when they do call, it’s obviously a smaller mistake than when they call a bet that is closer to pot-sized.
A large bet is often interpreted as either a very strong hand or a bluff rather than a thinnish value bet. Add to this the fact that many of your opponents are looking for excuses to call, and they will often decide that, having checked the flop and turn, they have invited you to bluff and therefore need to call the river.
This represents the problem with playing AK or AQ this way. After opening for pot from UTG and then checking twice, this player had essentially turned his hand face up. At that point, he’s got to play a guessing game on the river, since I know almost exactly what he has. How often will I bluff? How often will I value bet an underpair? He has no way of knowing. For what it’s worth, I’d suggest that your default play against an unknown whom you suspect to have AK is to make a lot of value bets on dry boards and not to bluff.