Poker is a card game of skill, luck and strategy where players make a series of betting decisions over the course of several rounds. Players place bets in a pot that is collected and added to at the end of each betting interval. The best five card poker hand wins the pot, including all bets placed in the previous intervals.
Unlike a game like chess, where information is made available to the players as they play each move, in poker it is impossible to know what any opponent holds until the end of the hand. This means that resources must be committed before all the facts are known and, in many cases, even as more cards are dealt, a player will not have complete command of the situation until the hand is completed.
This is one reason why the top players often call so many bets with their weaker hands, hoping that they will get lucky and see that extra card they need to make a straight or a flush. However, this type of playing style is expensive and usually a waste of money in the long run.
Instead, smart players know when to check and stay in the hand, or fold. This allows them to avoid throwing good money after bad, and to potentially chase off other players who may have been waiting for that extra card to improve their own hand. This strategy is called min-maxing. It involves maximizing the value of your winning hands, and minimising your losses on your losing hands, by making intelligent bets on the basis of probability, psychology and game theory.