casino

Blackjack Basic Strategy: Optimal Decisions

Basic strategy is the mathematically optimal set of decisions for every blackjack hand. Using it reduces the house edge to approximately 0.5%.

8 min read ยท Systems: probability

What is basic strategy?

Basic strategy is a set of decisions (hit, stand, double, split, surrender) derived from millions of computer simulations that maximizes expected value for every possible player hand vs dealer upcard combination. It does not guarantee winning โ€” it minimizes the house edge.

  • Basic strategy reduces house edge to โ‰ˆ0.5% in standard conditions
  • Without strategy, average player faces โ‰ˆ2โ€“3% house edge
  • Strategy varies slightly by number of decks and rule variations

Key strategy rules

The most important basic strategy rules: always split Aces and 8s; never split 5s or 10s; double on 10 or 11 when dealer shows low card; stand on hard 17+; hit soft 17 (Ace + 6); surrender hard 16 vs dealer 9, 10, Ace if allowed.

  • Hard 16 vs dealer 10: hit (expected loss is lower than standing)
  • Soft 18 (Ace+7) vs dealer 9, 10: hit โ€” standing has higher expected loss
  • Double down on 11 vs dealer 2โ€“10: adds positive EV even with risk

Card counting overview

Card counting tracks the proportion of high vs low cards remaining. The Hi-Lo count assigns +1 to 2โ€“6, 0 to 7โ€“9, and โˆ’1 to 10s and Aces. A high positive true count (running count / decks remaining) favors the player.

  • True count = running count / decks remaining
  • Players raise bets when true count is high (deck rich in 10s/Aces)
  • Counting is legal but casinos can ban suspected counters

Related calculators