Blackjack mathematics

The edge belongs to the ruleset, not to the word “blackjack.”

Two tables can look identical while offering meaningfully different expected returns.

Reviewed by the Baccaret Editorial Team · Updated
Benchmark

For one commonly analyzed six-deck game where the dealer stands on soft 17, correct basic strategy can reduce the house edge to roughly four-tenths of one percent. Change the rules and the figure changes.

Rules worth recording

RuleWhy it matters
Blackjack pays 3:2 or 6:5Changes the value of the strongest starting hand.
Dealer S17 or H17Changes dealer drawing behavior and strategy.
Number of decksChanges card composition and some strategy decisions.
Double after splitAffects value of splitting opportunities.
SurrenderAdds an exit option in selected poor situations.
Resplit / split-ace rulesChanges pair value.

Avoid fake precision

A page that says “blackjack has a 0.5% house edge” without stating its rules is incomplete. Baccaret will attach assumptions to every strategy table, calculator or comparison.