Gambling terms, explained straight

Poker

Poker hands probability

Poker hands probability measures how often a particular hand type appears in a deal, calculated by dividing the number of ways that hand can occur by the total number of possible hands.

Sample space
52-card deck yields 2,598,960 possible five-card hands1
Rarest hand
Royal flush occurs 4 ways; probability is about 1 in 649,740 (0.000154%)1
Calculation method
Count combinations producing the target hand, then divide by total possible hands12
Also called
Hand probability, poker hand odds, hand frequencies12

Key points

  • The probability of any five-card hand type equals its combination count divided by 2,598,960.1
  • In Texas hold ’em, hand strength is estimated by counting outs — unseen cards that improve the hand.3
  • Hand rankings are related to rarity but are not the same as probability; rankings order hand types, while probability measures their frequency.45

Five-card hand probabilities

Selected hand types from a 52-card deck.
Hand type Combinations Probability
Royal flush41 in 649,740
Straight flush (excl. royal)361 in 72,193
Four of a kind6241 in 4,165
Full house3,7441 in 694
Flush5,1081 in 508
Straight10,2001 in 255
Three of a kind54,9121 in 47
Two pair123,5521 in 21
One pair1,098,2401 in 2.37
High card1,302,5401 in 2.00

Where this term is used

Not the same as

  • Poker probability — a broader term covering all chance calculations in poker, not just hand outcomes
  • Poker hand rankings — the ordered strength of hand types, which is related to rarity but is not the probability itself

Sources

  1. Poker probability en.wikipedia.org Provides the sample space size, royal flush count, and calculation method for five-card hand probabilities.
  2. Rules of Card Games: Poker Hand Probabilities pagat.com Confirms the calculation method and alternative names for hand probability.
  3. Texas hold 'em en.wikipedia.org Supports the use of outs in Texas hold 'em for estimating hand strength.
  4. 343 arxiv.org Supports the distinction between hand rankings and probability.
  5. Ranking of Poker Hands pagat.com Supports the distinction between hand rankings and probability.

Sources are drawn from regulators, universities and published research, and each one is labelled with what it actually is — a preprint is not called a paper. Bookmaker and affiliate pages are never cited here, because a page that sells betting is not a neutral authority on it.