This is a discussion on The odds of flopping a St8 flush within the online poker forums, in the General Poker section; A couple of days ago at FT I flopped a 9 high st8 flush holding 96.
The odds of flopping a royal flush given two suited broadways → 0.005% or 1 in 19,600.
To see examples of calculating the odds of hitting a Straight Flush draw on the flop, check out the 888poker article on Royal Flush odds in poker. Odds of Making a Straight Flush on the Later Streets There will be two primary types of Straight Flush draw we’ll flop. Oct 15, 2010 From the Wizard's, 'Poker Probabilities' page on the WoO site, there are 5,108 ways to make a flush with five cards, out of 1,302,540 possible hands, or 1 in 255.The odds of another player having two cards of the same suit in the hole is 12 or, 1 in 1021. The royal flush is a case of the straight flush. It can be formed 4 ways (one for each suit), giving it a probability of 0.000154% and odds of 649,739: 1. When ace-low straights and ace-low straight flushes are not counted, the probabilities of each are reduced: straights and straight flushes each become 9/10 as common as they otherwise would be.
The Royal Flush is actually a type of straight flush. It is created when we hold T,J,Q,K,A all of the same suit.
To flop a Royal Flush, it is necessary to start the hand with precisely two suited cards between Ten and Ace. Regardless of which two of these cards, we hold the probability of flopping the straight flush will be the same.
This is because either way, we’ll need the flop to come down as three precise cards.
Odds of Making a Royal Flush on the Flop
Since there are exactly 19,600 different possible flops that can be dealt, the odds of flopping the Royal Flush are precisely 1 in 19,600. (To learn how the number of different flops can be calculated, check out the 888poker article on straight flush odds in poker.)
Odds of flopping the Royal Flush with two suited cards between Ten and Ace =
Odds of flopping the Royal Flush with two suited cards between Ten and Ace =
1/19,600 = 0.00005 or roughly 0.005%
Odds of Flopping the Royal Flush Straight Draw
Flopping the Royal Flush is virtually impossible. A slightly more likely possibility is that of flopping the Royal Flush straight draw.
We’d only need two specific cards to fall for this to be the case.
For example, imagine we hold the TdJd.
Flops that give us the Royal Flush draw with TJs
QdKdx (47 possible flops)
AdQdx (47 possible flops)
AdKdx (47 possible flops)
AdQdx (47 possible flops)
AdKdx (47 possible flops)
The third card can be any one of the remaining 48 cards left in the deck (aside from the card that actually gives us the straight flush.
This means 141 different possible flop combinations give us the straight flush (47 * 3).
Odds of flopping a straight flush draw with two suited cards between Ten and Ace = 141/19,600 = 0.0072 or roughly 0.72%.
That’s still less than 1% chance of flopping a Royal Flush draw even after starting out with a suited connector, but it is 141 times more likely than flopping the Royal Flush itself.
Similar logic can be applied to calculating the possibility of flopping straight flush draws when starting out with a suited connector. Although there are typically more ways to flop a straight flush draw than a Royal Flush draw.
For example, starting with T9s, there are 9 different ways of flopping a straight flush draw, making the probability three times more likely than flopping a Royal Flush draw with a holding such as QTs
Odds of Making the Royal Flush Postflop
There will be two primary types of Royal Flush draw we’ll flop. The gutshot Royal Flush draw and the open-ended Royal Flush draw.
Gutshot Royal Flush draws have 1 out in the deck, while open-ended Royal Flush draws have 2 outs in the deck.
Odds of Hitting on the Turn or River
Odds of catching the gutshot Royal Flush on the turn 1/47 = 0.0213 or roughly 2.1%
Odds of catching the open ended Royal Flush on the turn 2/47 = 0.426 or roughly 4.3%
Odds of catching the gutshot Royal Flush on the river 1/46 = 0.0217 or roughly 2.2%
Odds of catching the open-ended Royal Flush on the river 2/46 = 0.0435 or roughly 4.4%
Odds of Hitting by the River
To calculate the probability of hitting by the river, we’ll employ the trick of calculating the chance of not hitting and then subtracting from 100%.
Odds of not catching the gutshot Royal Flush on the turn 46/47
Odds of not catching the open-ended Royal Flush on the turn 45/47
Odds of not catching the gutshot Royal Flush on the river 45/46
Odds of not catching the open-ended Royal Flush on the river 44/46
Odds of not catching the gutshot Royal Flush on the turn or river = 46/47 * 45/46 = 0.9574 or roughly 95.7%
Odds of not catching the open-ended Royal Flush on the turn or river = 45/47 * 44/46 = 0.9158 or roughly 91.6%
Odds of hitting the gutshot Royal Flush by the river = (100 - 95.7%) roughly 4.3%
Odds of hitting the open-ended Royal Flush by the river = (100 – 91.6%) roughly 8.4%
Implied Odds Analysis of a Royal Flush
A Royal Flush always carries excellent implied odds when hitting. This is because our opponent is usually forced into stacking off with very strong worse hands - such as worse flushes and full houses.
Royal Flushes made with two of our hole cards always carry better implied odds than straight flushes made with one of our hole cards. When using just one of our hole cards, it means there will be four cards to the Royal Flush already on the board.
This scenario decreases the chance that our opponent will pay us off with worse holdings. It will be impossible for our opponent to make the nut flush since the highest possible card of the correct suit makes the Royal Flush, and we hold it ourselves.
Basic Strategy Advice
Unless all five cards of the Royal Flush appear on the board itself, it is impossible to ever chop with the Royal Flush. It is always the best hand, and we should be looking to invest as much of our stack as possible (preferably all of it).
Odds of Making Royal Flush | |
Method (Royal Flush) | Probability (%) |
Seeing a flop with two suited broadways | 0.01 |
Catching royal Flush Gutshot from flop to turn | 2.13 |
Catching royal Flush open ender from flop to turn | 4.26 |
Catching royal Flush Gutshot from turn to river | 2.17 |
Catching royal Flush open ender from turn to river | 4.35 |
Catching royal Flush Gutshot from flop to river | 4.30 |
Catching royal Flush open ender from turn to river | 8.42 |
Odds of flopping a Straight Flush draw | 0.72 |
The odds of flopping a straight flush with a premium suited connector such as T9s is 0.02% or 1 in 4,900
Definition of the Straight Flush –
Five cards of consecutive rank, all of the same suit.
Example – 5d6d7d8d9dThe Ten to Ace Straight Flush is the strongest hand in poker and is referred to as the “Royal Flush”.
Odds of Making a Straight Flush on the Flop
Flopping a Straight Flush seldom happens in poker. We specifically need to start out with two suited connected cards for this to be possible.
The odds of flopping a Straight Flush are so unlikely (0.02% or less) that the majority of poker equity calculators don’t even show the precise odds.
We’ll need to do some maths of our own.
Calculation of Straight Flush Odds
Let’s start with a very specific example -
We hold A2s. What are the odds of flopping the Ace to Five Straight Flush?
Why do we choose this example? It’s the easiest one because it provides only one way of making the Straight Flush. The flop has to come down precisely Three, Four, Five of the correct suit.
So, how likely is this?
In order to calculate, we’ll first need to know how many combinations of three cards are possible on the flop.
Basic Combinations and Permutations
Poker Odds Of Flopping A Royal Flush In Hold Em
Firstly, how many different combinations of three cards can be dealt on the flop? Assuming we care about the order of the three cards (and that our two hole cards are already known), the answer is 117,600 (50 * 49 * 48).
In statistics, this type of calculation is referred to as a permutation and accounts for the order of the flop cards.
Of course, in Hold’em, the order of the cards on the flop doesn’t matter (i.e. a 3,4,5 flop is the same as a 5,3,4 flop, for all intents and purposes). What we are interested in is the number of possible combinations of three cards.
A combination is similar to a permutation but doesn’t account for the order. Since there are 6 possible ways of arranging three cards, we can simply divide our number of permutations (117,600) by 6 to establish the number of possible three-card combinations on the flop.
117,600 / 6 = 19,600 possible combinations of three cards on the flop (given two cards are known)
In other words, there are 19,600 different possible sets of three cards that may fall on the flop given that our two hole cards are already known.
Guess what?
To make the exact Straight Flush in question, only one of these 19,600 combinations will do the job.
Armed with that information, we can now establish a range of different probabilities.
Odds of flopping the Straight Flush with A2s = 1/19,600 = 0.00005 or roughly 0.005%
That’s an insanely small likelihood!
Thankfully, the odds with different types of starting hands are usually a little better.
It all depends on the number of different combinations of three cards that provide a Straight Flush.
For example, think about T9s.
How many different ways are there to make a Straight Flush with 9Ts?
Ways of making a Straight Flush with T9s
JQK
QJ8
J87
678
QJ8
J87
678
So that’s four different ways. We are hence four times as likely to make a Straight Flush with 9Ts as we are to make a Straight Flush with A2s.
Odds of flopping the Straight Flush with 9Ts = 4/19,600 = 0.0002 or roughly 0.02%
Ways of making a Straight Flush with T8s
QJ9
J79
679
J79
679
Odds of flopping the Straight Flush with T8s = 3/19,600 = 0.00015 or roughly 0.015%
Ways of making a Straight Flush with T7s
J89
689
689
What Is A Royal Flush In Poker
Odds of flopping the Straight Flush with T7s = 2/19,600 = 0.0001 or roughly 0.01%
Only suited connectors (or gappers) can make Straight Flushes on the flop. All other holdings such as pocket-pairs and off-suit combos can never flop a Straight Flush.
We are, naturally, more likely to flop a Straight Flush draw as opposed to the Straight Flush itself. To see examples of calculating the odds of hitting a Straight Flush draw on the flop, check out the 888poker article on Royal Flush odds in poker.
Odds of Making a Straight Flush on the Later Streets
There will be two primary types of Straight Flush draw we’ll flop. The gutshot Straight Flush draw and the open-ended Straight Flush draw.
Gutshot Straight Flush draws have 1 out in the deck, while open ended Straight Flush draws have 2 outs in the deck.
Odds of Hitting on the Turn or River
Odds of catching the gutshot Straight Flush on the turn 1/47 = 0.0213 or roughly 2.1%
Odds of catching the open-ended Straight Flush on the turn 2/47 = 0.426 or roughly 4.3%
Odds of catching the gutshot Straight Flush on the river 1/46 = 0.0217 or roughly 2.2%
Odds of catching the open-ended Straight Flush on the river 2/46 = 0.0435 or roughly 4.4%
Odds of Hitting by the River
To calculate the probability of hitting by the river, we’ll employ the trick of calculating the possibility of not hitting and then subtracting from 100%.
Odds of not catching the gutshot Straight Flush on the turn 46/47
Odds of not catching the open-ended Straight Flush on the turn 45/47
Odds of not catching the gutshot Straight Flush on the river 45/46
Odds of not catching the open-ended Straight Flush on the river 44/46
Odds of not catching the gutshot Straight Flush on the turn or river = 46/47 * 45/46 = 0.9574 or roughly 95.7%
Odds of not catching the open-ended Straight Flush on the turn or river = 45/47 * 44/46 = 0.9158 or roughly 91.6%
Odds of hitting the gutshot Straight Flush by the river = (100- 95.7%) roughly 4.3%
Odds of hitting the open-ended Straight Flush by the river = (100 – 91.6%) roughly 8.4%
Implied Odds Analysis of a Straight Flush
A Straight Flush always carries excellent implied odds when hitting. This is because our opponent is usually forced into stacking off with very strong worse hands such as worse flushes and full houses.
Straight Flushes made with two of our hole cards always carry better implied odds than Straight Flushes made with one of our hole cards.
When using just one of our hole cards, it means there will be four cards to the Straight Flush already on the board. This decreases the chance that our opponent will pay us off with worse holdings.
Although Straight Flushes should hardly ever be folded, their implied odds are the best when no higher Straight Flush is possible on the board.
Basic Strategy Advice
It’s basically the nuts. Play aggressively and make big bets! Even if a higher Straight Flush is possible, it’s usually just a cooler if we are beat. We’d have to be really deep to find an exception.
Odds of Making Straight Flush | |
Method (Straight Flush) | Probability (%) |
Flopping the Straight Flush with A2s | 0.01 |
Flopping the Straight Flush with T9s | 0.02 |
Flopping the Straight Flush with T8s | 0.02 |
Flopping the Straight Flush with T7s | 0.02 |
Catching the Straight Flush Gutshot from flop to turn | 2.13 |
Catching the Straight Flush open ender from flop to turn | 4.26 |
Catching the Straight Flush Gutshot from turn to river | 2.17 |
Catching the Straight Flush open ender from turn to river | 4.35 |
Catching the Straight Flush Gutshot from flop to river | 4.30 |
Catching the Straight Flush open ender from flop to river | 8.42 |