mathematics
Game Theory Optimal (GTO)
Game theory optimal, or GTO, is a way of playing poker that cannot be exploited by opponents. A GTO strategy is balanced: even if the opponent knows exactly what you are doing, they cannot make more money against you than they would by playing the same strategy.
Gap Concept
The gap concept is a rule from David Sklansky which states that you need a stronger hand to call a raise than to open with a raise yourself. The reasoning is that when you open, you may win the pot without a fight, while a caller faces a player who has already shown strength.
GTO
GTO is short for game theory optimal, the strategy that cannot be exploited in the long run. Players use the abbreviation for solver-based study and for play based on balanced ranges.
ICM
ICM, the Independent Chip Model, is a method that turns the chips in a tournament into their cash value based on the prizes that remain. It shows that chips are worth less than their face value when the payouts are fixed.
Ideal Edge Odds
Ideal edge odds are the theoretical maximum edge odds, which are impossible to achieve. The phrase describes the best advantage a player could have, in theory.
Implied Odds
Implied odds are the odds that include the money you may win on later streets if you hit your draw. They allow a call that looks bad on the current pot odds alone to be profitable.
Insurance
Insurance is a side agreement in which a player pays another player a certain amount in exchange for a guarantee of winning a certain amount of money regardless of the outcome of the hand. In other contexts, it means a deal to split the pot.
Investment Odds
Investment odds are the estimated returns on betting investments. They describe how much a player can expect to receive for the amount he puts in.
Key Card
A key card is a card that gives you a big draw or makes your hand. When it comes, it changes the strength of your holding.
Lay Odds
To lay odds is to give favorable odds to an opponent. You risk more than you can win.
Long Odds
Long odds describe a very low probability that something will happen. A long shot is a hand that is unlikely to win.
M‑Ratio (M)
M-ratio, or M, measures how many rounds of forced bets your stack can pay for in a tournament. It is your stack divided by the cost of one orbit: the small blind, the big blind and the antes.
MDF
MDF stands for minimum defense frequency. It is the share of your range that you need to continue with when facing a bet so that your opponent cannot profit by bluffing with any hand.
Minimum Defense Frequency
Minimum defense frequency is the share of your range that you must continue with against a bet so that your opponent cannot make an automatic profit from bluffing. It is written MDF.
Nash Equilibrium
Nash equilibrium is a set of strategies in which no player can improve his result by changing his own strategy, if the others keep theirs. In poker, a Nash equilibrium strategy is one that cannot be exploited by the opponent.
Nut Advantage
Nut advantage is a situation in which one player is more likely than the other to hold the strongest hands on a board. It is one of the three main types of advantage in a hand, alongside positional advantage and range advantage.
Odds
Odds are the likelihood of an event, often written as a ratio. In poker, they are used to decide whether a call, fold or raise is profitable.
Odds Against
Odds against are the number of failures for each success. If something has odds of 4 to 1 against, it fails four times for every time it succeeds.
Odds For
Odds for are the number of attempts per success. If the odds for an event are 5 to 1, it happens once in five attempts.
Odds On
Odds on describes a situation in which an event is more likely to happen than not. A favorite is said to be odds on.
One‑Outer
A one-outer is a situation in which a player has only one card left in the deck that can make him win the hand. He is a huge underdog.
Out
An out is a card that will improve your hand to one that is likely to win. For example, with four cards to a flush, there are nine outs: the nine remaining cards of that suit.
Outs
Outs are the unseen cards that will improve a player's hand to one that is likely to win. For example, with four hearts, there are nine outs for a flush.
Overlay
An overlay is the shortfall in a tournament with a guaranteed prize pool when the entries do not bring in enough money. The casino or card room has to add the missing money, and so it takes a loss.
Pot Committed
Being pot committed means that you have already put so many chips in the pot that folding is no longer sensible, because the pot is large compared with the chips you have left.
Pot Odds
Pot odds are the ratio between the size of the pot and the cost of a call. They tell you how often you must win to make the call profitable.
Price
The price in poker is the amount that a player needs to call to stay in the hand. It is often used with pot odds, which compare the price with the pot.
Quartered
Quartered means that you win only a quarter of the pot in a hi-lo game, because you tie for one half of the pot with another player. For example, if you and another player share the nut low, each of you takes a quarter, while the high hand takes half.
Race
A race is a situation in which two players are all in with hands whose chances are close to even, such as a pair against two overcards. It is also called a coin flip.
Range
A range is the set of all hands that a player could have in a given situation. Instead of guessing one exact hand, good players think about the group of hands that fit their opponent's actions.
Range Advantage
Range advantage is a situation in which one player's overall range is stronger than the other's on a particular board. The player with it can bet more often and apply more pressure.
Re‑draw
A re-draw is a situation in which a player already has a strong hand but can still improve it on a later betting round. For example, a set with a flush draw has a re-draw to a flush.