Important Poker Probabilities

1. Important Poker Probabilities Cheat
2. Important Poker Math
3. Important Poker Probabilities Calculator
4. Important Poker Probabilities Rules
5. Important Poker Probabilities Games

Poker Mathematics. Poker is a game of skill and using the ability to read situations and opponents to give you the advantage in each hand you play. It is also a game of mathematics, where you should be able to calculate the odds of either you or your opponent winning the hand in any situation. Let's start with some rather simple but quite important odds: being dealt aces. There are 1,326 different hole-card combinations in Texas Hold'em poker and 6 of them are aces. Thus the odds of being dealt aces in any hand are 6 to 1,320 or 1 to 221 (or 0.45%). You probably already knew that. If only two players are remaining in a Texas Hold’em Poker hand before the flop, the odds of one player winning can range from 5% up to 95%. We have listed the most important preflop match-up probabilities and poker odds below.

Pot odds are the only difference between some winning and losing players - they are that important. So learn to compute them or memorize the chart, but make the commitment to use pot odds when playing poker. You'll never regret it, and neither will your bankroll.

Which poker stats are most important?

Our poker HUD software offers a large amount of statistics. Knowing which ones are relevant and important can be overwhelming. If you are new to poker software you can initially ignore all statistics except the essential three poker statistics. Once you have understood how to use the basic statistics, you can add more depending on your style of play, and your chosen table size.

The big three poker statistics (and one bonus stat):

• Voluntarily Put $ in Pot (VPIP)
• Preflop Raise (PFR)
• Postflop Aggression Frequency (Agg)
• A bonus stat: Big blinds won/100 hands.

These three statistics are a great starting point to get an idea of a person’s playing style. They only require 25 hands or so to reliably give a good idea of a player's tendencies.

Voluntarily Put $ in Pot (VPIP)

VPIP in poker measures how often you voluntarily pay money into a hand before seeing the flop. Paying the big blind, the small blind, or the ante is not considered voluntary. Therefore this percentage indicates how often you called, bet, or raised. The lower this value, the tighter your hand selection is. The higher, the looser. Only preflop betting is taken into account.

Good players know to only invest money in the pot when they have decent starting hands. A simple way to measure whether you are doing this is to keep your VPIP at a sensible value.

What is a good number for VPIP?

Simple answer: between 15% and 20%. This assumes you want to play tightly, you are playing micro-stakes, and you are playing on full ring cash tables.

Now the more complicated answer: it depends a lot. If you are still learning to play good poker, then you should be very selective in which hands you play, so your VPIP might acceptably be a tad lower than 15%. The less people on the table, the more hands you can play. If you are on a table full of ultralight players, you can also loosen up. An experienced player who understands the subtleties of the game can get away with a VPIP between 20% and 27%. In 6-max or heads-up, most players have a much higher VPIP. In Pot Limit Omaha, VPIP values will be even higher.

Preflop Raise (PFR)

The PFR statistic indicates how often you have raised before the flop is seen. A high value is an indicator of an aggressive player. A low value indicates a passive player. Good players are aggressive players.

Your PFR has a possible range between a minumum of 0% and a maximum equal to the value of your VPIP. That is, if your VPIP is 20%, then your PFR can’t be higher than 20%. Ideally it should be a little lower than your VPIP, but not much lower.

Poor players and beginners play timidly. They call too often preflop. Good players frequently fold or raise preflop, especially if no other players have yet raised. If you are not prepared to raise, then you should consider folding. Calling preflop just in case the flop is good for you is not a winning poker strategy.

What is a good PFR range?

Between 2% and 3% lower than VPIP. If your VPIP is 15%, PFR should be about 12%. These two numbers in combination indicate that you are only playing quality hole cards, and you are predominantly raising with them pre-flop. In other words, you are playing how most poker books and poker forums say you should play.

Important Poker Probabilities Cheat

Postflop Aggression Frequency (Agg)

Agg indicates how aggressively you play postflop. The higher this number, the more aggressively you are playing. This must be interpreted in combination with VPIP. Players who see very few flops will naturally tend to have a higher aggression percentage because they are only playing top-quality hole cards.

Poor players play passively postflop. They’ll check or call too often. Good players know to play good hands aggressively postflop:

• because players with speculative hands are forced to fold before they get free cards
• because if they hit the flop or have a dominating hand, a bet or raise will increase their return

What is a good Agg range?

50% to 60% is ideal, assuming that you have a VPIP of 15% to 20%. Much higher, and you are probably overplaying speculative hands and bad hands, and bluffing too much. Much lower and you are not playing your good hands strongly postflop.

Leave the bluffing for the movies and for live play. At low stakes online play, bluffing is much less important than a good understanding of the probabilities of winning hands.

Big blinds won/100 hands

The three stats I've presented so far mean nothing if you can't keep your win rate positive. A nice way to 'normalize' your win rate across different stake levels, table sizes, and opponents is to measure how much you won in terms of the big blind. If you are playing at a table where the big blind is $0.50, and you won $20, then think of this as winning 40 big blinds.

If this number is not positive, then you are losing money. The best remedy is to drop to a lower stake level, where the opponents are weaker. If, according to this stat, you consistently win over time, then you should consider going up to a higher stake level.

Adjusting your play based on the villain's poker stats

This is where our poker HUD software gets really useful: analyzing and exploiting opponent weaknesses. Let's consider some hypothetical players:

Tight Tim has VPIP of 5%, PFR of 5%, and Agg of 100%

With such a low VPIP, we can guess that this player folds anything except the very best hands. And with a PFR equal to VPIP, when he gets premium hands, he raises. So if this player raises, and you are next to act, you know that you should fold every hand except the best few hands, such as AA, KK, QQ. You can be almost certain that if you go to the flop, he'll raise postflop. So play tighter than usual with this player. But when you do get a premium hand, and he comes along, you can be sure that player B will put plenty of chips into the pot. Your pot, hopefully.

Passive Pete has VPIP of 20%, PFR of 16%, and Agg of 10%.

This player seems take have a good handle on preflop play. But when he gets to the flop, he gets timid. He is probably going to give you a chance postflop to see the turn and river for free. If you go to the flop with him and raise, there is a good chance he'll fold. So you can play a bit more aggressively both preflop and postflop.

Eddie the Eagle has VPIP of 22%, PFR of 19%, and Agg of 55%.

Eddie has a good all-round balance between preflop and postflop play. Preflop, he plays tight and aggressively. Postflop, he balances between pushing hard with his good hands, and being willing to fold or check with his weaker hands. Eddie would be well-served to move on to understanding more advanced poker statistics.

Tracking your poker stats

Poker players use poker software like Poker Copilot to automatically record their hands. Each hand is broken down into many statistics, which are then aggregated into simple percentages.

Poker Statistics Guide

What’s next after you’ve understood the basic poker stats? Read our Poker Statistics Guide for a comprehensive explanation of understanding and using all the main poker statistics.

This post works with 5-card Poker hands drawn from a standard deck of 52 cards. The discussion is mostly mathematical, using the Poker hands to illustrate counting techniques and calculation of probabilities

Working with poker hands is an excellent way to illustrate the counting techniques covered previously in this blog – multiplication principle, permutation and combination (also covered here). There are 2,598,960 many possible 5-card Poker hands. Thus the probability of obtaining any one specific hand is 1 in 2,598,960 (roughly 1 in 2.6 million). The probability of obtaining a given type of hands (e.g. three of a kind) is the number of possible hands for that type over 2,598,960. Thus this is primarily a counting exercise.

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Preliminary Calculation

Usually the order in which the cards are dealt is not important (except in the case of stud poker). Thus the following three examples point to the same poker hand. The only difference is the order in which the cards are dealt.

These are the same hand. Order is not important.

The number of possible 5-card poker hands would then be the same as the number of 5-element subsets of 52 objects. The following is the total number of 5-card poker hands drawn from a standard deck of 52 cards.

The notation is called the binomial coefficient and is pronounced “n choose r”, which is identical to the number of -element subsets of a set with objects. Other notations for are , and . Many calculators have a function for . Of course the calculation can also be done by definition by first calculating factorials.

Thus the probability of obtaining a specific hand (say, 2, 6, 10, K, A, all diamond) would be 1 in 2,598,960. If 5 cards are randomly drawn, what is the probability of getting a 5-card hand consisting of all diamond cards? It is

This is definitely a very rare event (less than 0.05% chance of happening). The numerator 1,287 is the number of hands consisting of all diamond cards, which is obtained by the following calculation.

The reasoning for the above calculation is that to draw a 5-card hand consisting of all diamond, we are drawing 5 cards from the 13 diamond cards and drawing zero cards from the other 39 cards. Since (there is only one way to draw nothing), is the number of hands with all diamonds.

If 5 cards are randomly drawn, what is the probability of getting a 5-card hand consisting of cards in one suit? The probability of getting all 5 cards in another suit (say heart) would also be 1287/2598960. So we have the following derivation.

Thus getting a hand with all cards in one suit is 4 times more likely than getting one with all diamond, but is still a rare event (with about a 0.2% chance of happening). Some of the higher ranked poker hands are in one suit but with additional strict requirements. They will be further discussed below.

Another example. What is the probability of obtaining a hand that has 3 diamonds and 2 hearts? The answer is 22308/2598960 = 0.008583433. The number of “3 diamond, 2 heart” hands is calculated as follows:

One theme that emerges is that the multiplication principle is behind the numerator of a poker hand probability. For example, we can think of the process to get a 5-card hand with 3 diamonds and 2 hearts in three steps. The first is to draw 3 cards from the 13 diamond cards, the second is to draw 2 cards from the 13 heart cards, and the third is to draw zero from the remaining 26 cards. The third step can be omitted since the number of ways of choosing zero is 1. In any case, the number of possible ways to carry out that 2-step (or 3-step) process is to multiply all the possibilities together.

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The Poker Hands

Here’s a ranking chart of the Poker hands.

The chart lists the rankings with an example for each ranking. The examples are a good reminder of the definitions. The highest ranking of them all is the royal flush, which consists of 5 consecutive cards in one suit with the highest card being Ace. There is only one such hand in each suit. Thus the chance for getting a royal flush is 4 in 2,598,960.

Royal flush is a specific example of a straight flush, which consists of 5 consecutive cards in one suit. There are 10 such hands in one suit. So there are 40 hands for straight flush in total. A flush is a hand with 5 cards in the same suit but not in consecutive order (or not in sequence). Thus the requirement for flush is considerably more relaxed than a straight flush. A straight is like a straight flush in that the 5 cards are in sequence but the 5 cards in a straight are not of the same suit. For a more in depth discussion on Poker hands, see the Wikipedia entry on Poker hands.

The counting for some of these hands is done in the next section. The definition of the hands can be inferred from the above chart. For the sake of completeness, the following table lists out the definition.

Definitions of Poker Hands

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Counting Poker Hands

Straight Flush
Counting from A-K-Q-J-10, K-Q-J-10-9, Q-J-10-9-8, …, 6-5-4-3-2 to 5-4-3-2-A, there are 10 hands that are in sequence in a given suit. So there are 40 straight flush hands all together.

Four of a Kind
There is only one way to have a four of a kind for a given rank. The fifth card can be any one of the remaining 48 cards. Thus there are 48 possibilities of a four of a kind in one rank. Thus there are 13 x 48 = 624 many four of a kind in total.

Full House
Let’s fix two ranks, say 2 and 8. How many ways can we have three of 2 and two of 8? We are choosing 3 cards out of the four 2’s and choosing 2 cards out of the four 8’s. That would be = 4 x 6 = 24. But the two ranks can be other ranks too. How many ways can we pick two ranks out of 13? That would be 13 x 12 = 156. So the total number of possibilities for Full House is

Note that the multiplication principle is at work here. When we pick two ranks, the number of ways is 13 x 12 = 156. Why did we not use = 78?

Important Poker Math

Flush
There are = 1,287 possible hands with all cards in the same suit. Recall that there are only 10 straight flush on a given suit. Thus of all the 5-card hands with all cards in a given suit, there are 1,287-10 = 1,277 hands that are not straight flush. Thus the total number of flush hands is 4 x 1277 = 5,108.

Straight
There are 10 five-consecutive sequences in 13 cards (as shown in the explanation for straight flush in this section). In each such sequence, there are 4 choices for each card (one for each suit). Thus the number of 5-card hands with 5 cards in sequence is . Then we need to subtract the number of straight flushes (40) from this number. Thus the number of straight is 10240 – 10 = 10,200.

Three of a Kind
There are 13 ranks (from A, K, …, to 2). We choose one of them to have 3 cards in that rank and two other ranks to have one card in each of those ranks. The following derivation reflects all the choosing in this process.

Important Poker Probabilities Calculator

Two Pair and One Pair
These two are left as exercises.

High Card
The count is the complement that makes up 2,598,960.

The following table gives the counts of all the poker hands. The probability is the fraction of the 2,598,960 hands that meet the requirement of the type of hands in question. Note that royal flush is not listed. This is because it is included in the count for straight flush. Royal flush is omitted so that he counts add up to 2,598,960.

Important Poker Probabilities Rules

Probabilities of Poker Hands

Important Poker Probabilities Games

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2017 – Dan Ma