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Explanation

A backdoor draw is a drawing hand that needs both the turn and river cards to improve to a made hand. Unlike a standard draw (which only needs one card), a backdoor draw has lower probability and is often factored into pot odds and implied odds calculations, especially in no-limit hold'em.

How It Works

• Backdoor flush draw: A hand that needs two more cards of the same suit on the turn and river to complete a flush. For example, holding two hearts with one heart on the flop gives a backdoor flush draw.
• Backdoor straight draw: A hand that needs two specific cards to complete a straight. For instance, holding 9-8 on a flop of 7-2-K gives a backdoor straight draw if both the turn and river are a ten and a six (or a six and a ten).

Probability and Odds

The probability of hitting a backdoor flush draw is approximately 4.2% from flop to river (about 22.5-to-1). For a backdoor straight draw, the odds vary depending on the number of possible runner-runner combinations. Generally, backdoor draws are long shots but can influence decision-making when combined with other equity.

Strategic Considerations

• Drawing to the nuts: A backdoor draw to the nuts (e.g., the nut flush or nut straight) may justify continuing in a hand if the pot odds are favorable, especially if the opponent is unlikely to pay off a flush if the draw completes.
• Semi-bluffing: Backdoor draws can be used as semi-bluffs. If you have a weak made hand plus a backdoor draw, you might bet to represent strength, with the possibility of improving to a strong hand later.
• Pot odds and implied odds: Because backdoor draws are unlikely, they contribute relatively little equity. However, in multi-way pots or deep-stacked situations, implied odds may make calling a small bet worthwhile.

Example

In Texas Hold'em, you hold A♠ 2♠ and the flop is K♠ 9♦ 4♠. You have a backdoor flush draw (needing two more spades). The chance of hitting a flush is low, but if the pot is large and your opponent checks, you might check behind or consider a small bet to see a turn cheaply.

Related Concepts

• Runner-runner: Another term for backdoor draws.
• Equity: The chance of winning a hand. Backdoor draws contribute a small percentage to total equity.
• Implied odds: The potential future winnings if you hit a backdoor draw, which can sometimes justify a call.

Overall, backdoor draws are a nuanced aspect of poker strategy, offering small additional equity that experienced players use to make profitable decisions in marginal situations.