Most poker authors recommend a tight-
aggressive approach to playing Texas hold 'em. This strategy involves playing relatively few hands (tight), but betting and raising often with those that one does play (aggressive). although the full consequences for optimal strategies remain to be explored. In addition, groups at the
University of Alberta and
Carnegie Mellon University worked to develop poker playing programs utilizing techniques in
game theory and
artificial intelligence. In January 2015, the
AAAS journal
Science reported that the group at the
University of Alberta had succeeded in coding a computer program called
Cepheus that can learn from its playing experience to optimize its
CFR algorithm and approach playing perfection when opposing strong players in the variant known as heads-up limit Texas Hold 'em, which involves only two players. Although it does not win every hand, it is unbeatable on average over a large number of hands. The program exhibits more variation in its tactics than professional players do, for instance bluffing with weak hands that professional players tend to fold. Public web access to observe and play against Cepheus is available.
Starting hands s is statistically the best hand to be dealt in Texas hold 'em poker. Because only two cards are dealt to each player, it is easy to characterize all of the starting hands. There are (52 × 51)/2 = 1,326 distinct possible
combinations of two cards from a standard 52-card deck. Because
no suit is more powerful than another, many of these can be equated for the analysis of starting-hand strategy. For example, although and are distinct combinations of cards by rank and suit, they are of equal value as starting hands. Because of this equivalence, there are only 169 effectively different hole-card combinations. Thirteen of these are pairs, from deuces (twos) to aces. There are 78 ways to have two cards of different rank (12 possible hands containing one ace, 11 possible hands containing one king but no ace, 10 possible hands containing one queen but no ace or king, etc.). Both hole cards can be used in a
flush if they are suited, but pairs are never suited, so there would be 13 possible pairs, 78 possible suited non-pairs, and 78 possible unsuited ("off-suit") non-pairs, for a total of 169 possible hands. Suited starting hands are stronger than their unsuited counterparts, although the magnitude of this strength advantage in different games is debated. Because of the limited number of starting hands, most strategy guides include a detailed discussion of each of them. This distinguishes hold 'em from other poker games where the number of starting card combinations forces strategy guides to group hands into broad categories. Another result of this small number is the proliferation of
colloquial names for individual hands.
Strategic differences in betting structures Texas Hold'em is commonly played both as a
"cash" or "ring" game and as a
tournament game. Strategy for these different forms can vary.
Cash games Before the advent of
poker tournaments, all poker games were played with real money where players bet actual currency (or chips that represented currency). Games that feature wagering actual money on individual hands are still very common and are referred to as "cash games" or "ring games". The
no-limit and
fixed-limit cash-game versions of hold 'em are strategically very different. Doyle Brunson claims that "the games are so different that there are
not many players who rank with the best in both types of hold 'em. Many no-limit players have difficulty
gearing down for limit, while limit players often lack the courage and 'feel' necessary to excel at no-limit."
Tournaments Texas hold 'em is often associated with poker tournaments largely because it is played as the main event in many of the famous tournaments, including the
World Series of Poker's Main Event, and is the most common tournament overall. Traditionally, a poker tournament is played with
chips that represent a player's stake in the tournament. Standard play allows all entrants to "buy-in" for a fixed amount and all players begin with an equal value of chips. Play proceeds until one player has accumulated all the chips in play or a deal is made among the remaining players to "
chop" the remaining prize pool. The money pool is redistributed to the players in relation to the place they finished in the tournament. Only a small percentage of the players receive any money, with the majority receiving nothing. "The percentages are not standardized, but common rules of thumb call for one table" (usually nine players) "to get paid for each 100 entrants," according to poker author
Andrew Glazer, in his book, ''The Complete Idiot's Guide to Poker''. A good rule of thumb is that close to 10% of players will be paid in a tournament. As a result, the strategy in poker tournaments can be very different from a cash game. Proper strategy in tournaments can vary widely depending on the amount of chips one has, the stage of the tournament, the amount of chips others have, and the playing styles of one's opponents.
Evaluating a hand One of the most important things in Texas hold'em is knowing how to evaluate a hand. The strategy of playing each hand can be very different according to the strength of the hand. For example, on a strong hand, a player might want to try to appear weak in order to not scare off other players with weaker hands, while on a weak hand, a player might try to bluff other players into folding. There are several ways to evaluate hand strength; two of the most common are counting
outs and using calculators.
Counting outs This method consists of counting the cards still in the deck, which in combination with the cards the player already has can give the player a potentially winning hand. Such cards are called "outs", and hand strength can be measured by how many outs are still in the deck (if there are many outs then the probability to get one of them is high and therefore the hand is strong). The following chart determines the probability of hitting outs (bettering the player's hand) based on how many cards are left in the deck and the draw type. Multiplying the number of outs by two or four (the Two Times Rule or Four Times Rule) gives a reasonable approximation to the One Card % or Two Card %, respectively, in the above table. For example, an open straight draw on the flop has 8 outs so the odds to hit the straight on the turn is 16% (8 x 2) and the odds on the river is 32% (8 x 4).
Calculators Calculators are
poker tools that calculate the odds of a hand (combined with the cards on the table if there are any) to win the game. Calculators provide precise odds but they cannot be used in live games and are therefore mostly used on Internet poker games. The first known commercial poker calculator was marketed by Mike Caro. Michael Shackleford, the Wizard of Odds, later made one available to the public free of charge on his website. == Similar games ==