A straight flush is a poker hand consisting of five cards in unbroken rank sequence that are all of the exact same suit, such as 5-6-7-8-9 of hearts. It stands as the second-strongest hand category in standard poker, outranking four of a kind. Only a higher straight flush can defeat a straight flush.

This page is general information, not legal advice.

Understanding the Straight Flush

To form a straight flush, your hand must satisfy two distinct requirements simultaneously:

  1. Unbroken Sequence: The five cards must follow a continuous numerical or rank progression (for example, 4-5-6-7-8).
  2. Matching Suit: All five cards must share the exact same suit (all spades, all hearts, all diamonds, or all clubs).

If a hand has five cards in numerical order but contains mixed suits, it is simply a standard straight. If a hand has five cards of the same suit but their ranks do not form a sequence, it is a standard flush. A straight flush combines both elements into one hand.

In standard poker hand rankings, the royal flush is simply the highest possible straight flush (10-J-Q-K-A of a single suit). The royal flush is not a separate hand category; it is the top-ranking sequence within the straight flush category.

Straight Flush Hand Example

Here is a verified example of how a player completes a straight flush using hole cards and community cards:

Suppose your starting hole cards are 9h 8h (the nine of hearts and eight of hearts).

The dealer puts out community cards reading 7h 6h 5h Kd 2c.

To evaluate your hand, combine your hole cards with the community cards to pick the best five-card combination:

  • Your cards: 9h, 8h
  • Community cards used: 7h, 6h, 5h (while ignoring the Kd and 2c)

Your final five-card hand consists of 9h, 8h, 7h, 6h, and 5h. Because these five cards run sequentially from 5 through 9 and every single card is a heart, you have completed a straight flush. The board provides three hearts, and your two hole cards provide two hearts, fulfilling both the suit and sequence requirements without any duplicate cards.

Straight Flush vs. Other Poker Hands

Understanding how a straight flush compares to other hands ensures you evaluate your position correctly at the table:

  • vs. Four of a Kind: A straight flush beats four of a kind.
  • vs. Standard Straight: A normal straight features consecutive ranks but mixed suits. Any straight flush defeats a normal straight regardless of the numerical ranks involved.
  • vs. Nut Flush: A nut flush is the highest possible standard flush, but it lacks sequential ranks. To learn more about high flush combinations, read our guide on what is the nut flush in poker. Any straight flush beats a nut flush.
  • vs. Another Straight Flush: If two or more players complete a straight flush in the same hand, the player with the higher card at the top of the sequence wins the pot. For instance, a sequence ending in a 9 beats a sequence ending in an 8. If two players share the exact same five ranks, the pot is split. Suits never break ties in poker hand evaluations.

Mathematics and Odds

Evaluating the probability of holding a straight flush depends heavily on the specific model used to calculate the math.

In the basic 5-card model (where a player receives exactly five cards from a standard 52-card deck), there are 2,598,960 total possible five-card hand combinations. Within those combinations:

  • There are exactly 40 straight flushes (this total includes royal flushes).
  • The probability of being dealt a straight flush in a five-card hand is approximately 0.0015%.
  • Expressed as odds, this is roughly 1 in 65,000 hands.

It is important to note that this math applies strictly to the 5-card model. It does NOT represent the 7-card probability calculated in games like Texas Hold’em, where players select five cards out of seven available cards.

FAQ

Is a royal flush different from a straight flush?

No, a royal flush is not a separate hand category. It is simply the highest possible straight flush, running specifically from 10 to Ace in a single suit.

Can suits be used to break a tie between two straight flushes?

No. Suits have no ranking hierarchy in standard poker rules. If two players hold a straight flush of identical numerical ranks, the hand results in a tie and the pot is split evenly.

What beats a straight flush?

Only a higher-ranking straight flush can beat a straight flush. For example, a straight flush running 6-7-8-9-10 defeats a straight flush running 5-6-7-8-9.

Does a straight flush beat four of a kind?

Yes, a straight flush ranks higher than four of a kind in the standard hand rankings.

Understanding how hands are ranked helps players evaluate board textures and make clear decisions during a game.