Blackjack Basic Strategy: What It Is and What It Isn’t

Blackjack is unusual among casino games because the player makes decisions that change the outcome. Whether to hit, stand, double or split has a measurable effect on the house edge. “Basic strategy” is simply the set of decisions that minimises that edge for a given set of rules.

Where basic strategy comes from

The strategy is derived by calculating, for every combination of player hand and dealer up-card, which action produces the best expected result. It was first worked out by hand in the 1950s and later confirmed by computer simulation. The result is a chart — usually a grid with the player’s total down the side and the dealer’s card along the top.

Played perfectly, basic strategy brings the house edge on a typical online game (six or eight decks, dealer stands on soft 17, double after split allowed) to roughly 0.5%. A player guessing or following instinct typically gives up 2–4%.

Core principles

You don’t need to memorise every cell to capture most of the benefit. The main patterns:

• Stand on hard 17 or higher. Always.
• Hit hard 8 or lower. Always.
• Hard 12–16 depends on the dealer. Stand when the dealer shows 2–6 (they’re more likely to bust); hit when the dealer shows 7 or higher.
• Double on 11 against anything except an ace; double on 10 against 2–9.
• Always split aces and eights. Never split tens or fives.
• Soft hands (containing an ace counted as 11) are more forgiving: soft 18 stands against 2–8 but hits against 9, 10 or ace.

What basic strategy isn’t

It isn’t card counting. Counting tracks the ratio of high to low cards remaining in a shoe and adjusts bets accordingly. It requires a physical shoe that isn’t reshuffled after every hand, which online RNG blackjack always is. Live dealer games do use physical shoes, but they are typically cut deep and reshuffled frequently, and operators can restrict players they suspect of counting.

It isn’t a winning system. A 0.5% edge is still an edge. Over £1,000 of hands you’d expect to lose about £5 — far less than on most slots, but still a loss.

It isn’t universal. Rule variations shift the optimal play. If the dealer hits soft 17, or doubling is restricted, some cells change. Use a chart generated for the rules of the table you’re at.

Side bets

Perfect Pairs, 21+3 and similar side bets carry house edges of 3–10%, many times higher than the main game. Basic strategy doesn’t apply to them; the only consistent approach is to leave them alone.

How to learn it

Keep a chart open while you play in demo mode. After a few hundred hands the common situations become automatic. Free strategy trainers exist that quiz you on decisions and flag errors.

The honest summary

Basic strategy is the difference between a game that costs about 50p per £100 wagered and one that costs £3 or £4. It is worth learning for anyone who plays blackjack regularly. It is not a route to profit, and any site claiming otherwise is selling something.

Play with a fixed budget and treat blackjack as entertainment with a low cost, not an income. Support: BeGambleAware.org.