Poker Odds Flush Draw After Flop

In the third part of the Paul Phua Poker School series on poker odds, Paul Phua gives tips on predicting the future to improve your present strategy

Would it not be wonderful to have the power to predict the future? It would certainly be easy to make money at betting! Film-lovers will recall how using a sports almanac from the future made Biff Tannen a rich man in the second Back to the Future film.
We can’t all have a DeLorean time machine, but in poker we have the next best thing. We have the ability to predict what is likely to happen in the future, and to change our strategy accordingly.
In the first two parts in this mini-series on poker odds, I gave tips on why odds are important, and how to calculate them using a simple magic formula. We have seen already how knowing our likelihood of winning will affect how much we bet. Now here is an interesting application in practical play:

How to play a nut flush draw

Draw

An Inside Straight Draw on the Turn or River: Hole Cards: Flop: 16.5%. An Open-Ended Straight Draw on the Turn or River: Hole Cards: Flop: 31.5%. A Flush Draw on the Turn or River: Hole Cards: Flop: 35%. A Flush Draw or Open-Ended Straight Draw on the Turn or River: Hole Cards: Flop: 54.1%.

  • Dear Wizard, In video poker, what are the odds of drawing the following cards to a royal flush? Dealt a royal flush. I am asking the question because I recently hit a royal flush after holding 2 cards the ace and jack of diamonds and then drew the ten, queen and king of diamonds.
  • Your Texas Hold'em poker odds are given below for hitting a draw by the river with a given number of outs after the flop and turn, and examples of draws with specified numbers of poker outs given. Example: if you hold 22 and the flop does not contain a 2, the odds of hitting a 2 on the turn is 22:1 (4%).
Poker Odds Flush Draw After Flop

As I said in my video on the best pre-flop hands, a suited Ace has great potential as a starting hand, even if your kicker is low. An Ace on the flop often gives you the best hand, though be prepared to fold to opposition if your kicker is weak. And if you flop a flush draw, you are in a very powerful position – more powerful than many people realise.
Let’s take the starting hand shown in my video: A4 of diamonds. The flop comes K5 of diamonds, with a 9 of spades. Another player bets. First, do what you should always do when someone bets: work out what hand they are likely to hold.
There’s no strong straight draw out there; if he has a flush draw it’s worse than yours; sets are uncommon. You can’t put him on AK, as he didn’t seem that strong in pre-flop betting, so you reckon he has a K: maybe KQ or KJ. So he likely has top pair, and you have nothing – yet! But you have great potential. Let’s work out how much.

Count up your “outs”

There are nine diamonds left to come that complete our flush, plus three Aces to give us a higher pair: that’s 12 “outs”. Using our magic formula for calculating the odds, that gives us 12 x 4 = 48% chance of winning by the river. [Mathematicians say the real figure is 45% –the magic formula isn’t perfect, but it’s close enough.]
That’s a nearly 1 in 2 chance of winning the pot! Pretty good odds. But the great thing about poker is it’s not all cold, hard math. It takes strategy and psychology to decide how to play those odds.
Your instinct here will be to call, and hope to hit. That’s a reasonable strategy, and the more people who are in the hand, the better it is. You will likely take all their money if you hit your nut flush – thus being paid several times your investment.
But let’s look at another, more advanced strategy, one that is particularly valuable if only one other player is in the hand.

Re-raising for “fold equity”

Unless you are keen to keep a number of people in the pot, a great tactic against a single opponent is to re-raise rather than call. Re-raising gives you “fold equity”. That’s a fancy way of saying it gives you an extra chance at winning: if they get scared and fold, congratulations! You’ve won the pot with the worst hand. And if they call, you’re still a coin-flip to win by the river.
To have fold equity, your bet should be big enough to make them fold. Simply doubling their bet is almost never enough. Even a weak King is likely to call and hope you are semi-bluffing with a flush draw (which you are!), or that they hit two pair on the turn.
So how much do you raise? That calls for psychology: is this player a holder or a folder? Some people are “calling stations” who will call almost any bet with a pair. With a person like this, you may need to raise bigger. Either way, do it confidently. If you are relatively short-stacked, you can even shove all-in. Don’t worry! You are nearly 50-50 to win even if they call.

If they do call – what next?

Maybe they realise you’re on flush draw. Maybe they’re just stubborn. Whichever, your opponent calls you, and the turn card is a blank – it doesn’t help. What now?
Usually now you have no fold equity: if they called a re-raise on the flop, they will often feel committed to call a bet on the turn. And now you have only one card left to come, not two, so your chances of winning are halved to than 1 in 4.
Unless you are a very experienced player with a strong read that your opponent may fold, it’s not worth inflating the pot with what are now poor odds of winning. You want to check. The good news is, your opponent will be wary of you and will usually also check, so you get a “free” card to see the river.
To sum up: when you re-raise on the flop, you have maybe a coin-flip chance of them folding to give you a small pot; and a coin-flip chance of them calling, in which case you then have a coin-flip chance of winning a big pot. Three quarters of the time, therefore, you are winning with a re-raise!

Other flush draws

Let’s just look quickly at other flush draw combinations that you might not be aware of.
Two more outs: Let’s say there was a 4 on the flop rather than the 5, giving your A4 of diamonds a small pair. Now you have two additional outs (either of the two 4s still to come would give you three of a kind to beat his pair of Kings), so you are even better than 50%.
Three more outs: Or let’s say the flop came K52. Now with your A4 you additionally have an inside straight draw, giving three extra outs. (There are four 3s that would make a straight. One of these is a diamond and you’ve already counted that out in your flush draw, hence three extra outs not four).
Three fewer outs: The flush draw to beware of is where you have no extra outs, just the nine cards for your flush. The magic formula tells us that your chances then are just 9 x 4 = 36%, ie 1 in 3. It’s a big leak in less experienced players’ strategy to chase this kind of flush draw against a single opponent.

In my next article on poker odds and strategy…

Poker Odds Flush Draw After Flop Rule

I hope the above example shows how knowing the odds – our own probability time machine that lets us peer into future likely outcomes – helps dictate our present strategy. In my next article, I will give you a useful chart of the most common. Learn it well! Read the next article.