Reverse implied odds refer to how much you can expect to lose if you make your draw, but your opponent still comes out with a better hand. Implied odds, on the other hand, refer to how much you stand to win after you make your draw. Here's another way to think about it: implied odds apply when you have a drawing hand and you want to see if you stand a chance of running down your competition who may have a made hand; reverse implied odds apply when you have a made hand and your opponent is drawing.
Much like implied odds, there is no exact equation you can use to calculate your reverse implied odds. What you can do, however, is calculate your pot odds, which will help you determine if your call is looking ‘big picture’ profitable.
How to Use Reverse Implied Odds to Help Paint the Big Picture
Once you've used your pot odds to get a handle on your implied odds (i.e. to see if you should call a bet), you should round out your perspective by working out your reverse implied odds (i.e. to see if calling to complete a draw is a good idea). Reverse implied odds are particularly important to consider when you find yourself in a pot with lots of action and multiple opponents. If you’ve flopped the nuts, you won’t even be bothering to look into reverse implied odds; only concern yourself with this concept when you’ve made the draw, but there’s also a good chance your competition has a good chance of making a better draw.
We'll look at an example using 2 opponents to shed some light on what we mean:
Your hand: 5♠ 4♣
Flop: 6♥ 7♦ T♥
Opponent #1 bets and opponent #2 calls.
Now you have to give some serious consideration to your hand to see if it has what it takes to be the best hand if you make your draw. Again, you are going to want to calculate your pot odds to glean your chances of making the draw.
In this situation, an 8 or 3 could complete your straight, but it could also complete a better straight for either of your opponents. What's more, if we suppose those cards were 8♥ or 3♥, then one of our opponents could very well have a flush. When situations like this crop up, we have reverse implied odds since even if we make the draw, there's a good chance it won't be the best hand. If you don't have the pot odds to make calling the first bet profitable, you should fold. Your reverse implied odds overshadow any remote implied odds you may hold. (Even completing the hand chasing a draw will very likely result in your losing money.)
Accurately inferring your reverse implied odds doesn’t require a calculator. You’re just going to need to employ some good old fashioned common sense.
In general, it is unwise to call on low straights or weak flushes since it’s highly likely an opponent is betting to make a bigger flush. (Example: We hold 6♦ 7♦ and the flop comes 4♦ 8♠ Q♦. This is a weak flush, so if you don't have the pot odds to call, bow out. Also, when you're chasing a straight or flush, be wary of boards that have pairs since those have all the makings of a full house for your competition.)
Reverse Odds: Big Picture Profitable
When it comes to calculating reverse implied odds, implied odds, expected value, value bets, and a good many of the key value assessments in poker, you can't think of the equation strictly as a way to work out whether or not your hand will win or lose in that particular instance. Rather, the astounding merits of many of these equations rests in their ability to help you determine whether or not you’re making a profitable call overall; whether, in the grand scheme of things, making the play is profitable.
We’ve said it more than once, and we'll say it again (and again) because it bears repeating: you don't have to win every hand to play winning poker - you just have to win more often than not over the course of your poker life. This is what we’re talking about when we refer to the 'big picture' or the 'long-run'. We are talking about overarching profitability, not specifics. Undeniably, the specifics of each hand are important to consider, but you can't get too focused on them when considering the merit of a play overall. The same hand that just lost you a sizable chunk of your stack could have actually been a very good hand that would usually have won most of the time. Just not that time, and that's tough luck. That's also poker. Reverse implied odds are another way of giving you a healthy hit of perspective – something that can be sorely lacking when we’re caught up in a superficially alluring, but fundamentally rotten hand.