What are "effective odds"?

[Depraved]

In another forum, there was some talk about "effective odds", and I was wondering if any of the experts here could give some kind of explanation for just what they are.

[J.R.]

I'm no expert.

Hold'em: 1 limper, you limp with T9s, button raises, you and the limpers call.

Flop AJ7.

1st limper bets, do you call getting 8-1 on your gutshot?

Well, 8-1 reflects your immediate odds, but since the pre-flop raiser is behind you, your effective odds may be worse as you expect the pre-flop raiser to raise the flop. Your effective odds are more like 11-2, since you expect the pre-flop raiser to raise the flop and the 1st limper to call.

Effective odds come into play when you are not closing the action on a street or may have to face additional bets on future streets. For example, if you decide to call down a turn check-raiser, you will likely have to put one bet into the pot on the turn and river, so you need to realize that the 6-1 pot odds you are facing on the turn are not the odds you really face because of the river bet. Your effective odds facing the turn check-raise scenario are 7-2, since you will have to call a river bet as well.