[jetsetboy]

IMO just calling the $1 flop is a mistake not because it's EV- but because raising has more value.

We have a FD, TPTK (hum), a GS, 3 other players. By raising this weak bet we achieve 3 things :
_ We define the hands of the 3 vilains, any pair might feel he is good here, the $1 bet means nothing at this point, I like to know how much vilains like their hand, because when I hit I want to be able to bet as much as they can reasonably call.
_ We build the pot. If we hit our flush we will know for sure that we have the best hand so we will want to play a huge pot. If we call the 1$ bet, the pot will be $8 on turn if SB and BB both call. With a possible flush on the board we will not be able to stack somebody if nobody has a good flush (J high +). How do you react on this board with a set if a donk weak lead the flop, a good player just call, the turn is a spade and the good player goes crazy ? You just call if you have the odds for a fh and don't call a strong bet on the river ui. If he raised on the flop you will be more inclined to call. Don't be too result oriented, if we get 3betted that's not a big deal as the pot will still be of a reasonable size on the turn (except if we got 3betted to something like $25 and SB and BB both calls but then we would have direct pot odds for our call of the 3bet).
_ By calling we just put money in, offering terrific odds to SB and BB (who can call with 2 overs). By raising we don't allow them to stay for free. Nobody will ever fold a fd here (because it's likely that UTG will call/raise the bet given that he is a fish) so the one type of hand we want to keep we us will stay. We might make fold 77-99 which is actually a very good thing and two high cards will surely fold. This is a good thing too because if a J comes on the turn we might be in deep trouble if SB/BB leads and the two others folds.

Once we raised, SB called, UTG+1 3betted for $15 I guess a call is the best line. If SB push and UTG fold (worst case scenario) we still have the odds to call (I think, i'm not sure i haven't done the math). If SB calls too, we will have to reevalute on a blank turn depending on the size of the likely bet from UTG+1.

Don't forget that the fisrt bet and even a call of a raise from any player could be any overpair (in fact any pp as 22 gives an oesd), any two pairs, 65s, any fd. Against any of those hands which are far more likely than a set/straight we have 18 outs (any 2, any ace, any 5, any spade) !

By the way, fold this hand preflop in this position (except is the table is REALLY passive). I don't mind a raise to isolate the 40% VPIP fish if you think you will be HU more than 50% of the time or if you think you can win the pot preflop. I hate a limp, way to passive and most of the time you will be oop or you will have to fold because a mp/late player will raise.

Last but no least, quite often you raise on the flop and nobody calls, you have some FE. I think at least 33% and that's enough because you are quite happy to win the pot right here where any pp is SB/SA of you and there is 3 players in the pot.