Poker hands are the foundation of any poker game. In this article, we will discuss three types of poker hands: two pair, one pair, and high card.

Two Pair (K♣ K♦ 9♠ 9♥ 5♥)

A two pair hand is a combination of five cards where two of them share the same rank. The remaining three cards are called kickers and do not have to match each other or the pair. In the example above, K♣ K♦ 9♠ 9♥ 5♥, we can see that there are two pairs: kings and nines.

In five-card poker, there are 123,552 possible combinations of two pair hands. The probability of getting a two pair hand is approximately 1 in 416.

In seven-card poker, the frequency of two pair hands is 31,433,400, with a probability of about 23.5% [2].

One Pair (4♥ 4♠ K♠ 10♦ 5♠)

A one pair hand is a combination of five cards where one card shares the same rank as another card in the hand. The remaining three cards do not have to match each other or the pair. In the example above, 4♥ 4♠ K♠ 10♦ 5♠, we can see that there is only one pair: fours.

In five-card poker, there are 1,098,240 possible combinations of one pair hands. The probability of getting a one pair hand is approximately 1 in 2.36.

In seven-card poker, the frequency of one pair hands is 58,627,800, with a probability of about 43.8% [2]. Unlike five-card poker, one pair hands are more common than "no pair" (high card) in seven-card poker.

High Card (K♥ J♥ 8♣ 7♦ 4♠)

A high card hand is any combination of five cards that do not form a two pair, one pair, or three of a kind. In this case, the highest card determines the value of the hand. If multiple hands have the same highest card, the next highest card is used to determine the winner, and so on.

High card hands are often referred to as "nothing" or "garbage." The lowest possible high card hand is 7, with a probability of about 1 in 2.58.

In five-card poker, there are 2,598,960 possible combinations of cards that do not form two pair, one pair, or straight or flush. Therefore, the probability of getting a "no pair" (high card) hand is approximately 1 in 5.14.

In seven-card poker, the frequency of "no pair" (high card) hands is 23,294,460, with a probability of about 17.4% [2].

References:

[1] "Glossary". PokerTips.com. Retrieved February 26, 2013.

[2] Brian Alspach. "7-Card Poker Hands". January 18, 2000. Retrieved February 26, 2013.

[3] David Sklansky. Small Stakes Hold 'Em (1st edition). Page 127.

[4] "Trips Poker Term — Definition of the Poker Term Trips". About.com. Archived from the original on March 27, 2013. Retrieved February 26, 2013.