A Flush is five cards of one suit that are not in sequence. It is the fifth strongest hand in the poker hand rankings. Four hands beat it: a Royal Flush, a Straight Flush, Four of a Kind and a Full House.
How it works
All five cards share one suit: spades, hearts, diamonds or clubs. The ranks can be anything, as long as the cards do not run consecutively. Five hearts in a row would be a Straight Flush, and 10♠J♠Q♠K♠A♠ is a Royal Flush. Both outrank a plain Flush.
In Texas Hold’em you usually make one with two suited hole cards and three more of that suit on the board. Holding four cards of a suit after the flop is a flush draw. Nine cards complete it, about a 35% chance by the river.
What beats a flush
Four hands beat a Flush:
- Full House - three of a kind plus a pair, 3,744 combinations.
- Four of a Kind - four cards of one rank, 624 combinations.
- Straight Flush - five consecutive cards of one suit, 36 combinations.
- Royal Flush - the top straight flush, 4 combinations.
Everything below a Flush loses to it: a Straight, Three of a Kind, Two Pair, One Pair and High Card.
Does a flush beat a straight?
Yes, and this is the ranking question players ask most. The confusion comes from how the hands look while you are drawing to them: a Straight needs five cards in exact order.
The counts say otherwise. In a five-card deal there are 10,200 Straights but only 5,108 Flushes. A Flush is exactly twice as rare, which is why it ranks higher.
Flush or full house
One step above a Flush sits the Full House, and there the gap is small: 3,744 against 5,108. A Flush lands only 1.36 times as often, but that is enough to put the Full House higher.
Comparing two flushes
Compare the highest card first, then the next, and so on. Ace-high beats King-high, and A-Q-9-5-3 beats A-J-9-5-3 on the second card.
There are 1,277 distinguishable Flushes: every set of five ranks except the ten sequences that would make a Straight Flush. Each comes in four suits, which is where 5,108 comes from. The suit itself has no value: a Flush in spades is not worth more than the same Flush in hearts. Two identical Flushes split the pot.
Probability
There are two ways to count it, and the numbers are far apart.
- In a five-card deal: 5,108 combinations out of 2,598,960 - that is 0.1965%, or about 1 in 509.
- In seven-card Hold’em: 4,047,644 out of 133,784,560 - that is 3.03%, or about 1 in 33 hands to the river.
The five-card number comes out by subtraction: 4 suits x 1,287 sets of five ranks = 5,148, minus the 40 straight flushes = 5,108.
The gap between the two numbers explains why a Flush feels common at the table. Out of seven cards it lands about 15 times more often than out of five.