Blackjack strategy: the complete basic strategy chart and the maths holding it up

Blackjack strategy is not a belief system, and that alone separates it from every roulette "system" doing the rounds. It is the output of a complete calculation covering every possible hand against every possible dealer card, checked against computer simulation billions of times over. This guide from the blackjack academy hands you the full chart for the rule set you will meet most often online, explains the reasoning behind each line, puts a number on what it saves you, then goes on to insurance, card counting and the side bets that quietly undo all of it.

Basic strategy chart: hard totals

A hard total has no ace counted as 11. Key: H = hit, S = stand, D = double (hit if doubling is not allowed), Rs = surrender if offered, otherwise stand, Rh = surrender if offered, otherwise hit.

Basic strategy chart: soft totals

A soft total counts an ace as 11. Since it cannot bust on a single card, you double far more freely here. Ds = double if allowed, otherwise stand.

Basic strategy chart: pairs

P = split. Where the chart tells you not to split, play the hand as its hard total (5,5 = hard 10; 10,10 = hard 20). The 2,2 / 3,3 / 4,4 / 6,6 splits against small cards depend on DAS being available; without DAS, always hit 4,4, hit 2,2 and 3,3 against a 2 and 3, and hit 6,6 against a 2.

Adjustments for other rule sets

• Dealer hits soft 17 (H17): double 11 against an ace; double A,8 (soft 19) against a 6; double A,7 against a 2; surrender 15 and 17 against an ace (17 only where surrender exists — otherwise stand). Nothing else moves.
• European no-hole-card (ENHC): the dealer can still turn up blackjack after you have doubled or split, and you lose the extra bets with it. So do not double 11 against a 10; do not split A,A or 8,8 against an ace; do not split 8,8 against a 10. Hit those instead.
• No DAS: see the pairs note above. Doubling only on 10–11: hit the hands marked D on 9 and on all soft totals.
• Single and double deck: a handful of extra doubles and splits become correct (doubling 9 against a 2 and 11 against an ace in single deck, for instance). Use a deck-specific chart; carrying the multi-deck chart over there costs you only about 0.03%.

Why basic strategy works

Every line in the chart answers one question: for this hand against this up-card, which action carries the highest expected value? The answers cluster into a handful of patterns, which is what makes the chart far easier to hold in your head than 300 separate cells.

What ignoring the chart costs you

The average self-taught player sits somewhere near 2% — five times what the same table costs when played correctly. Ten minutes a day on the basic strategy trainer for one week closes that gap for good, and it costs nothing but a little data. Whenever a hand leaves you unsure, the blackjack chance calculator shows the expected value of each option.

Insurance: the maths

Insurance is a side bet that the dealer's hole card is a ten-value card, offered whenever the up-card is an ace. It pays 2 to 1 and you may stake up to half your original bet. Whether it is worth taking hangs on exactly one number: the share of ten-value cards still sitting in the shoe.

Insurance would only break even if more than one card in three left in the shoe were a ten (33.3%). A fresh shoe holds 30.8%, and the cards in your own hand nudge it lower still. Only a counter who knows the shoe is ten-rich (a Hi-Lo true count around +3 or better) has any business taking it. Even money on your own blackjack is the same bet in different clothing: you are turning down an expected 1.5 × 69.3% = 1.039 units to lock in a guaranteed 1.0 unit — a 3.9% donation.

Card counting: what it does, and why it barely functions online

Basic strategy assumes a freshly shuffled shoe. Card counting tracks how far the remaining shoe has drifted from that. A shoe rich in tens and aces favours you — more blackjacks paid at 3:2, more winning doubles, more dealer busts from stiff hands — while a shoe stuffed with small cards favours the dealer. Counters raise their bets when the shoe is rich and drop to the minimum when it is poor. It is legal everywhere, and the casino is equally free to refuse your action.

The Hi-Lo system

1. 1

   Keep the running count

   Start from 0 after the shuffle. Add or subtract the value of every card you see, other players' and the dealer's included. A full deck sums to zero, which is what makes it a balanced count.

2. 2

   Convert to a true count

   Divide the running count by the number of decks still to be dealt. A running count of +8 with four decks left is a true count of +2; that same +8 with one deck left is +8. The true count is the figure that measures your edge.

3. 3

   Size your bet

   Each true-count point is worth roughly 0.5% to the player. Starting from −0.4% at a good table, you are about break-even at +1, roughly +0.5% at +2 and +1% at +3. A typical spread bets 1 unit at true count ≤ 1, then 2, 4 and 8 units at +2, +3 and +4 or above (a 1–8 spread in 6 decks; 1–12 is common in 8).

4. 4

   Adjust a few plays

   The most valuable deviations — the "Illustrious 18" — include taking insurance at +3, standing on 16 vs 10 at 0 or higher, standing on 15 vs 10 at +4, and doubling 10 vs 10 at +4. Everything outside that list stays basic strategy.

Executed well in a casino with 75%+ penetration and a 1–12 spread, Hi-Lo returns around 0.5–1% of the average bet over the long run — with a standard deviation of more than one bet per hand, which is exactly why counters need bankrolls of 500–1,000 units to ride out the swings.

Why counting collapses online

With eight decks dealt only to the halfway mark, high true counts almost never arrive before the shuffle — the very moments you would be betting big get cut away. Add a slow game and the operator's standing right to close your account, and live dealer counting is a hobby rather than an edge. Anyone in a Telegram group selling you a course on "online card counting" is selling a course, nothing more.

Side bets to walk past

Almost every online table dangles optional side bets in front of you. They are separate wagers, they leave the main game's edge untouched, and they are priced like slot machines. Exact figures depend on the paytable and the deck count; the ranges below cover the common versions.

Put ₦10,000 on the main hand at 0.4% and ₦5,000 on 21+3 at 5% and your expected loss is ₦40 on the game and ₦250 on the side bet. That is six times the cost for half the stake. If you want one long-shot in your session it is still cheaper than most, but do not tell yourself you are playing blackjack when you place it.

Bankroll for blackjack

Blackjack's edge is small and its variance is anything but. Standard deviation runs at about 1.15 bets per hand once doubles and splits are counted, so over 100 hands at ₦10,000 your expected result is −₦4,000 with a one-standard-deviation range of roughly ±₦115,000. Losing runs of eight hands or more turn up about once every 300 hands, so plan for them rather than being shocked by them. A session bankroll of 50 units and a stop-loss you genuinely respect are the bare minimum; the bankroll management guide covers unit sizing, session limits and how the maths shifts once you add a bet spread.

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