well executed semi-bluff by me, or choke by them?

just got back from an afternoon session, including this hand:

2-5 NL, i'm sitting 9 handed with about 750 in front of me, on the button with Qd-10s

The blind is raised to 25 early, 4 callers including me, the BB and the SB.
The flop is Ah-Kh-4d. Check, bet of 75, call, call, call, fold.
Turn is Qc. Check, bet of 100, call, call, fold.
River is 4h. Now, the board is paired, plus there is a possible flush and straight draw out there. To my amazement, both guys check in front of me. I know my pair isn't good enough, but I also have the sense that the pot is mine for the taking, for a number of reasons. I mess with my chips for about 30 seconds, count out 250, then slide it past the line and recount it out.
The first guy squirms a bit, checks his cards a few times, then mucks it. The other guy folds quickly, but turns his face up to show K-Q. The first guy then says "at least I had that beat" which prompts me to show my cards as well...

i dont understand the flop call if you only have 750, but whatever. the river bet is a standard position bluff that will work 50% of the time. given that the heart hit on the river but paired the board, someone with a flush who is a winning player could have easily checked his flush and check/called a river bet. but looks as if it was good timing on your part so nh.

Preflop: I don't really like the call, regardless of how deep you were. Unless the raiser is either LAG preflop/passive-tight postflop or maniacal on all streets it seems pretty difficult to turn a profit here with the QTo. It's not that bad though.

Flop: Fold. You only have 3 outs to the nuts and reverse-implied odds on the turn and reverse-implied odds if you hit the jack of hearts and someone has a flush. Moreover, you are unlikely to take the pot down by bluffing on later streets. AK4 in a raised pot is a flop that hits people; more often than not no one's going anywhere, especially in these loosey-goosey live games.

Turn: Double fold, you get 0 action on a J or T (and the T may not even be an out) and you're not getting odds on a queen.

River: I have already expressed how I feel about your play based on straight odds. Perhaps you think you have bluffing equity later in the hand that can compensate for a lack of straight odds. My thoughts on this, in numbered form:

1. If you think your hand is disguised enough to hit a monster pot with a gutshot draw, then must you put them on a strong enough hand to pay you off to begin with. This is in direct conflict with your bluffing equity, i.e. the greater implied odds you have the less bluffing equity you have, the greater bluffing equity you have the more implied odds you have, etc.
2. If you intend to represent a strong hand on a non-heart river, it is a very unbelievable bluff. What strong made hand smooth-calls two streets with that many people in and a flush draw on the flop? This would be a terrible spot to bluff.
3. Representing a flush is also not that great of an idea since it is extremely likely someone in there has a flush draw to begin with. Representing what someone else just hit can be a very expensive proposition, especially considering the pot has become this big already.
4. Getting this out-of-line in multiway pots... just don't do it. I've been trained to almost never fuck around in multiway pots because it just gets way too costly and it's much less likely these questionable plays will turn a profit with that many people in. You have to have very observant and talented opponents to play this unconventionally at all, and even then you save most of your unconventional play for heads-up pots.
5. In the actual hand the 4 of hearts popped. This is a pretty bad card, as anyone with half a brain is going to shoot for a check-raise with AA-QQ... so you have fewer bluffing outs than before and if you hit a board-pairing flush card it costs you the pot and a big bet.

That being said, if I got to this river and it was somehow checked to me I would probably still bet it. It sounds like you generally have a tight image, and if you have been getting respect and you just look at them and feel they're weak a bet here is a very nice shot. AA-QQ have you in bad shape cause they shoot for a check-raise, and 56 of hearts will likely check-call, but it sounds like you don't think they're very strong. So take it down. But just remember you spent a lot of money to see this river and a lot of things had to fall into place.

btw this is a bluff, not a semi-bluff :)

yeah a semibluff is just a bluff with outs to improve, not a made losing hand. =)

copycat

it's funny how things happen in live play; how hands evolve, how you get stuck in pots you never intended to, how you tell yourself you'll see a flop and if you don't hit it hard you'll fold but still get involved, how you never intend to bluff at a pot but the opportunity suddenly pops up, basically how you get involved in the wrong pot at the right time...

three major factors in my decision to make a play at the pot: they both checked it to me on the river, thier obvious uncomfortable nature after the river both pairs the board and creates a flush possibility, and my tight-aggressive rep

I am amazed you got two people to fold offering them 4-1 odds. Either they saw you as frog's-ass-tight or as the type of player who hangs around with JTo and gets a lucky turn. Or maybe they are online players used to playing against donks who will play out any two suited cards religiously. :)