[I am fish]

I am going to attempt an example.

Let's say you are playing $10/20 and in the Big Blind you hold 98s.

A Player raises from middle position, the small blind calls, and you call in the big blind.

6 small bets so far ($60)...

The flop comes A 7 5 ... rainbow, but none of your suit.

Now, the person in the small blind who is first to act bets into you. You appear to be getting 7 to 1 for a call. However, behind you yet to act is the preflop raiser which makes a raise behind you more likely. You should consider what this would do to your pot odds. If it is raised behind you and the small blind calls, you will have put in $20 to win $100, thus reducing your odds to 5 to 1.

If you knew it would not be raised behind you, then it may be worth it to call when the small blind bets the flop. You are a 10.75 to 1 dog to hit your gutshot straight, but because you could expect to pick up at least 2 big bets (4 small bets) you could call getting 7 to 1 immediate odds knowing you are getting at least 11 to 1 implied odds on your 10.75 to 1 odds to hit your hand.

Let's go through this example hypothetically...
Let's assume that you call the small blind's bet, it gets raised behind you, the small blind calls and you call. As I said before, this is the equivalent of getting 5 to 1 odds as you have put in $20 to win $100. The odds against you hitting your gutshot draw on the turn is 10.75 to 1. Meaning you will miss your draw 10.75 times for every 1 time that you do hit it. Let us assume that if you miss your draw, your opponents will bet on the turn and you will fold. And... if you make your draw you will win the hand you will get one big bet from each of your opponents on both the turn and the river.

So, the 10.75 times that you fold on the turn, you will have lost $215.00 (10.75 x $20).

The one time you hit your draw you win the $100 dollars your that was there from the flop, plus you gain 4 big bets from your two opponents $80, for a total of $180.00

That means over 11.75 hands, you lose an average of $35... giving you a negative expectation of about $3 per hand.

Thus with these assumptions, when you get raised in this situation... over time... you lose money. You'll wish that you had never called in the first place.

However, at the point in the hand after you called the 1st bet and it gets raised behind you and the small blind calls... then you must call the 2nd... because at that point in the hand you are getting 11 to 1 for a call closing the betting. Whenever you are getting proper odds to win the hand, you must call... if you don't you are losing money. So assuming you folded every time in this situation... you would lose $10 per hand (the original bet you called).

So to recap, you would make money in this hand if you knew it would not be raised behind you but could expect to pick up at least 2 more big bets.

If it was raised behind you, and you called, you would lose money for the hand over time in this situation.

And if it was raised behind you, but you fail to call the 2nd bet when you were getting proper odds, you lose the most out of these 3 scenarios.

Of course, it's hard to say what would really happen for the rest of the hand. But I think this example gives a general idea of the concepts... Although, I may have just complicated everything for you.

Hope this helps.