Part III: Business & Regulation · Gambling Mathematics & Probability

38. Outs

Poker Math

Outs are the remaining cards in the deck that will improve a player’s hand to what they believe is the winning hand. Counting outs is the fundamental step in calculating drawing odds and equity. Common out counts include: 9 outs for a flush draw (13 cards of the suit minus 4 already visible), 8 outs for an open-ended straight draw, 4 outs for a gutshot straight draw, and 6 outs for two overcards. The “Rule of 2 and 4” provides a quick approximation: multiplying outs by 2 gives the approximate percentage chance of hitting on the next card, while multiplying by 4 gives the approximate chance of hitting by the river from the flop. Surveillance personnel should understand that players counting outs are engaging in standard poker strategy, not angle-shooting.

In practice

Not all outs are “clean” — some may improve the opponent’s hand as well (e.g., a flush draw card that pairs the board, potentially giving an opponent a full house). Discounted outs account for this by reducing the effective out count.

One entry from the Casino Industry Glossary — 1,157 terms written for surveillance, compliance and operations professionals rather than for players. Definitions describe industry usage; where a term carries a regulatory meaning, verify against the instrument that governs your jurisdiction.