POKER HANDS FOUR OF A KIND
FOUR OF A KIND-four cards of the same rank, such as four 9s or four Aces. In Hold'em, at least one pair must appear on the board for someone to have four of a kind. For example: if you are dealt two 9s, the other two 9s must appear on the board for you to have four 9s. You can also have four 9s if three 9s appear on the board and you hold the remaining 9. If two pairs are on the board, it is possible for two players to have four of a kind. In this case, the rank of the cards forming the hand determines the rank of the hand (four 9s beat four 8s). If all four 9s appear on the board, then all players have four 9s as their hand. To win the hand in this circumstance, one of your pocket cards must be higher than anyone else's pocket card and higher than the fifth card on the board. This illustrates an important concept in Hold'em—the kicker. A kicker is a pocket card that is not part of the combination, but decides ties. If the fifth card on the board is higher than anyone's kicker, all players have the exactly the same hand and the pot is split.
Odds of Making Four of a Kind From a Pocket Pair
The chance that a player holding a pocket pair will get both of the remaining matching cards from the next five cards in the deck is 2.15%
This can be calculated as follows: (2/50 + 2/49 + 2/48 + 2/47 + 2/46) * (1/50 + 1/49 + 1/48 + 1/47 + 1/46) which = .0215.
In the above example the player holding Ace King Suited wins. In poker the best five cards win, Although both players have four of a kind off of the board, the Ace makes the best five cards.