[nightlyraver]

I disagree with you 100%. First, we don't know that Villian does not have an A. He wants to protect against the flush draw PLUS Hero is presumably a very aggressive player. In this spot, I'm definately betting out with an A since Hero will be tempted to come over the top (as he did). Second, it's very nice that Hero has all those outs, but he's getting very poos odds to draw to them. A major part of the value of Hero's semi-bluff check-raise is that Villian will fold a better hand. In this spot, there is a 0% chance that Villian folds an A or a K and a 100% chance that he folds a pure bluff. Which brings me back to my original post - if Villian will check a hand like pocket 5's preflop, will fold a hand like this to a check-raise on the flop, AND will bluff at this with air a fair amount of time, only THEN is the check-raise semi-bluff worth it. I believe that all of those conditions must happen something like 60% of the time for the play to break even, but I may be wrong with the math. In this spot, I would really need to know my oponent to say the all of these conditions, combined, will occur 60% of the time or more. To say that more often than not he makes this bet with air is not supported by the OP.