Part III: Business & Regulation · Gambling Mathematics & Probability

26. True Count

Blackjack Math

The true count is the running count divided by the estimated number of decks remaining in the shoe, providing a normalized measure of deck composition that is independent of how many cards have been dealt. This conversion is essential because a running count of +10 is much more favorable when only one deck remains than when five decks remain. The true count is used to determine both bet sizing (larger bets at higher positive true counts) and playing deviations from basic strategy. Each increase of +1 in the true count shifts the player’s advantage by approximately 0.5%. Surveillance personnel understand that a player making large bets only in positive true count situations is a strong indicator of card counting.

In practice

Formula: True Count = Running Count / Decks Remaining. True count conversion requires estimating remaining decks, which experienced counters do visually. Some advanced systems (like KO) are “unbalanced” and eliminate true count conversion at the cost of slightly reduced accuracy.

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.