Advanced Blackjack Strategy
Advanced blackjack strategy adds count deviations, surrender indices and bet spreads to basic strategy. Full Illustrious 18 and Fab 4 tables and bankrolls.
Advanced blackjack strategy is everything you add on top of basic strategy once you know what has already come out of the shoe. Almost all of it depends on card counting, and almost none of it works in an RNG game that reshuffles every hand. This page sets out the four layers of advanced play, gives the full deviation tables with their Hi-Lo true count indices, and puts numbers on what each layer is worth and what bankroll it needs.
A warning before the tables. Basic strategy must be automatic first. A player who deviates correctly at the right counts but makes one basic blackjack strategy error every 20 hands is worse off than a player who never deviates at all. If you cannot play 100 hands on a blackjack strategy trainer without a mistake, that is the next step, not this page. And as with every page on this site: no strategy guarantees a win, and the edges quoted here are long-run averages that will not show up in any single session.
What counts as advanced
| Layer | What it is | Worth, roughly | Needs a count? |
|---|---|---|---|
| Composition-dependent plays | Deciding by the exact cards in your hand, not just the total | 0.01% to 0.04% in six decks | No |
| Count-based deviations (Illustrious 18) | Changing stand, hit, double, split and insurance decisions when the true count passes an index | Around 0.2% to 0.3% of the total counting gain | Yes |
| Surrender deviations (Fab 4) | Surrendering stiff hands at counts where the hit is worse than giving up half | Around 0.05% to 0.1%, only where late surrender is offered | Yes |
| Bet spreads | Betting more when the count favours you and the minimum when it does not | The bulk of a counter's edge, typically 0.5% to 1% at a 1-8 spread | Yes |
The ordering matters. Bet spreads do most of the work; playing deviations add a smaller amount on top; surrender deviations add a smaller amount again; composition-dependent plays are worth so little that they are covered separately on the perfect blackjack strategy page. A counter who gets the bet spread right and ignores every deviation keeps most of the available edge.
Composition-dependent plays
These need no count and apply to a freshly shuffled shoe. They are the only places where perfect play disagrees with the basic strategy chart, and the gap between the two options in each case is a fraction of a per cent.
| Hand | Dealer | Basic strategy | Composition-dependent play | Game |
|---|---|---|---|---|
| Hard 16 of three or more cards | 10 | Surrender, else hit | Stand | Multi-deck |
| Hard 16 containing a 4 or 5 | 10 | Surrender, else hit | Stand if no surrender | Multi-deck |
| Hard 15 of three or more cards | 10 | Surrender, else hit | Hit rather than surrender | Multi-deck |
| 8,8 | 10 | Split | Surrender under restrictive rules (no DAS or H17) | Multi-deck, late surrender |
| Hard 12 as 10-2 | 4 | Stand | Hit | Single deck only |
The full table with reasons is on the perfect blackjack strategy page. Combined, these are worth 0.01% to 0.04%. Learn the multi-card 16 v 10 stand and ignore the rest unless you play very high volume.
Deviations by true count
A deviation is a departure from basic strategy triggered by the true count. The Illustrious 18, compiled by Don Schlesinger, are the eighteen deviations that capture most of the value available from playing decisions. The indices below are for Hi-Lo (2 to 6 count +1, 7 to 9 count 0, 10 to ace count -1, true count = running count divided by decks remaining) in a multi-deck game. Take the listed action at or above the index; play basic strategy below it. Four of the entries have negative or zero indices, which means they tell you when to stop standing and start hitting as the count falls.
| # | Hand | Dealer | Index (Hi-Lo true count) | Action at or above index | Basic strategy play |
|---|---|---|---|---|---|
| 1 | Insurance | A | +3 | Take insurance | Never insure |
| 2 | 16 | 10 | 0 | Stand | Hit (or surrender) |
| 3 | 15 | 10 | +4 | Stand | Hit (or surrender) |
| 4 | 10,10 | 5 | +5 | Split | Stand |
| 5 | 10,10 | 6 | +4 | Split | Stand |
| 6 | 10 | 10 | +4 | Double | Hit |
| 7 | 12 | 3 | +2 | Stand | Hit |
| 8 | 12 | 2 | +3 | Stand | Hit |
| 9 | 11 | A | +1 | Double | Hit (S17) |
| 10 | 9 | 2 | +1 | Double | Hit |
| 11 | 10 | A | +4 | Double | Hit |
| 12 | 9 | 7 | +3 | Double | Hit |
| 13 | 16 | 9 | +5 | Stand | Hit (or surrender) |
| 14 | 13 | 2 | -1 | Stand at -1 or above, hit below | Stand |
| 15 | 12 | 4 | 0 | Stand at 0 or above, hit below | Stand |
| 16 | 12 | 5 | -2 | Stand at -2 or above, hit below | Stand |
| 17 | 12 | 6 | -1 | Stand at -1 or above, hit below | Stand |
| 18 | 13 | 3 | -2 | Stand at -2 or above, hit below | Stand |
The table assumes a multi-deck S17 game. Indices shift by a point or so under H17 or in single and double deck; published index tables for your exact rules exist and should be used if you are serious about this. Where late surrender is offered, the Fab 4 entries in the next section take priority over entries 2 and 3 at the counts shown there.
The five most valuable deviations
The first five rows carry a large share of the value of the whole table. If you only learn five, learn these.
1. Insurance at +3. Insurance is a side bet that the dealer has a ten in the hole. Off the top of a six-deck shoe the true odds are roughly 2.2 to 1 against, the bet pays 2 to 1, and the house edge is around 7%. At a true count of +3 or more, the shoe is rich enough in tens that the odds drop below 2 to 1 and the bet becomes profitable. This single deviation is worth more than any other because it applies to every hand you hold when the dealer shows an ace, and because you will be betting big at exactly the counts where it triggers.
2. 16 v 10, stand at 0. Basic strategy hits (or surrenders) 16 against a 10 because the bust chance is 62% and standing only wins when the dealer busts, which happens about 23% of the time. At a neutral or positive count the shoe holds more tens than small cards, so the hit busts even more often and the dealer's chance of busting edges up. The two options are close at a count of 0, which is why the index sits there; above it, standing is clearly better. This is the most frequent deviation you will make.
3. 15 v 10, stand at +4. Same reasoning as 16 v 10, but 15 needs a 6 or lower to improve, so a higher count is needed before standing overtakes hitting. Below +4, hit or surrender as per basic strategy.
4. 10,10 v 5, split at +5, and 5. 10,10 v 6, split at +4. A pair of tens is a 20 and stands under basic strategy. At a high count, each split 10 starts a hand that will often draw another ten for a second 20, against a dealer 5 or 6 that busts around 42% of the time. The split turns one strong hand into two, with a larger stake on the table at a count where you already hold the edge. It attracts attention in a casino, so some counters skip it deliberately.
Worked example of the value: at a true count of +4 with a £50 bet out, standing on 10,10 v 6 wins roughly 85% of the time for an expected return around +£35. Splitting puts £100 on the table and returns roughly +£45 to £50 in expectation. The gain is around £10 to £15 on one hand, which is why the index is where it is, and why the hand matters despite being rare.
Surrender deviations, the Fab 4
Where late surrender is offered, four further deviations cover the hands where giving up half the stake beats playing on. Surrender at or above the index; play basic strategy below it.
| Hand | Dealer | Index (Hi-Lo true count) | Action at or above index | Basic strategy play |
|---|---|---|---|---|
| 14 | 10 | +3 | Surrender | Hit |
| 15 | 10 | 0 | Surrender | Surrender (S17) |
| 15 | 9 | +2 | Surrender | Hit |
| 15 | A | +1 | Surrender | Hit (S17), surrender (H17) |
The 15 v 10 row has an index of 0 because basic strategy already surrenders it in the reference S17 game. The useful information is the other direction: below 0, hit it instead. The Fab 4 together are worth around 0.05% to 0.1%, which is small, but they are easy to remember and cost nothing to apply. In UK casinos and most UK online live games surrender is not offered, so these four rows do not apply; see the UK blackjack strategy guide for what changes without it.
Bet spreads and bankroll
The spread is the ratio between your minimum bet at neutral or negative counts and your maximum bet at high counts. A wider spread earns more because more money goes out when you hold the edge, but it also means larger swings and draws more attention at a live table. The figures below are approximate and assume a six-deck game, S17, DAS, 75% penetration, Hi-Lo with the Illustrious 18 and a rough ramp of one extra unit per true count point from +1. Rule changes, penetration and ramp design move all of them.
| Spread | Rough player edge | Bankroll for low risk of ruin (about 1% to 5%) | Example at £10 minimum |
|---|---|---|---|
| 1 to 4 | About 0.2% to 0.5% | Around 500 to 600 max bets | £40 max bet, £20,000 to £24,000 |
| 1 to 8 | About 0.5% to 1% | Around 400 to 500 max bets | £80 max bet, £32,000 to £40,000 |
| 1 to 12 | About 0.8% to 1.3% | Around 400 to 500 max bets | £120 max bet, £48,000 to £60,000 |
Two things stand out. First, even the best row is a small edge: at 1 to 12, 60 hands an hour and an average bet of perhaps £25, expected profit is around £15 to £20 an hour before expenses, with hourly swings of several hundred pounds. Second, the bankroll numbers are large because the edge is small and the variance is high. A counter with a 1 to 8 spread and a £5,000 bankroll at a £10 table is overbetting badly and has a high chance of losing the lot in normal variance, despite playing with an edge.
The betting strategy page covers why progressions such as Martingale do not change expected value. Bet spreading is the only form of bet variation that does, and only because it is driven by information about the shoe.
Back-counting and when to sit down
Back-counting, or Wonging after Stanford Wong, means counting from behind the table and only sitting down when the shoe is favourable. It removes the hands you would otherwise play at a disadvantage, which is most of them, and it narrows the spread you need because you never bet the minimum at a bad count.
| Decision | Rule of thumb |
|---|---|
| When to start watching | A fresh shoe, standing where you can see every card |
| When to sit down | True count reaches +1 to +2, depending on rules (closer to +2 under H17 or no hole card) |
| What to bet on entry | Already near the top of your ramp for that count, not the minimum |
| When to leave | True count drops to 0 or below, or the cut card appears |
| When it is not worth it | Casinos with no mid-shoe entry rules, crowded tables, or a shoe cut at 50% |
A six-deck shoe at 75% penetration gives about four and a half decks of play. The count is at +1 or better for perhaps a quarter to a third of hands dealt, so a back-counter plays far fewer hands per hour than a seated player but every one of them is at an advantage. The obvious drawback is that standing behind a table and sitting down only when the count is high is the single most recognisable counting behaviour, and most UK casinos either prohibit mid-shoe entry or watch for it.
What is realistic online
Honest answer: very little of this page works online, and it should be said plainly rather than implied otherwise.
| Game type | Shuffle | Can you count? | Do deviations help? |
|---|---|---|---|
| RNG blackjack (software) | Reshuffled every hand | No, the count resets to zero each hand | No; only composition-dependent plays apply, worth 0.01% to 0.04% |
| Live dealer, standard shoe | 8 decks, typically cut at around 50% | Technically yes, but 50% penetration is not workable | Marginal; the count rarely gets high enough to matter |
| Live dealer with continuous shuffling machine | Cards returned and reshuffled continuously | No | No |
| Live dealer, deep-cut shoe (rare) | 6 or 8 decks, 70% or more | Yes, with a seat and patience | Yes, as at a land-based table |
Most UK live blackjack studios deal eight decks and cut the shoe around halfway, which means the true count seldom reaches the +3 or +4 that the valuable deviations need. Infinite and unlimited-seat games sometimes shuffle more often again. Counting online is rarely worthwhile; the online blackjack strategy guide covers what does matter there, which is finding the best rules and playing basic strategy without error.
Frequently asked questions
Is advanced blackjack strategy legal in the UK?
Yes. Card counting and strategy deviations use only what you can see and remember, and there is no law against it. A casino is a private business and can ask you to leave, restrict your bets or shuffle more often if it believes you are counting, and UK casinos do all three. Using a device or software at a live table is a different matter and is prohibited.
How much more does advanced strategy win?
Playing deviations alone, without varying bets, are worth around 0.2% to 0.3%, which under typical rules takes a basic strategy player from a 0.4% to 0.5% disadvantage to roughly break-even. The real gain is from the bet spread: a 1 to 8 spread in a six-deck S17 DAS game with 75% penetration gives a rough player edge of 0.5% to 1%. That is the long-run average; short-term results vary enormously.
Do I need advanced strategy?
If you play RNG games online, no, because nothing on this page beyond composition-dependent plays applies. If you play live and want to play as well as possible at a flat bet, the Illustrious 18 are worth learning but add only a fraction of a per cent. If you want a genuine edge, you need the count, the deviations, the spread and a bankroll of several hundred maximum bets, and the edge you get is around 1%.
What is a blackjack strategy deviation?
A deviation is a change from the basic strategy play for a hand, made because the true count has crossed an index number. Standing on 16 against a 10 at a true count of 0 or above, or taking insurance at +3, are the two most common. Below the index you play basic strategy as normal.
What is the difference between basic and advanced blackjack strategy?
Basic strategy is the best play for your hand against the dealer's up-card assuming you know nothing about the rest of the shoe; it gets the house edge to about 0.4% to 0.5%. Advanced strategy uses information about the cards already dealt, through a count, to change both the play and the bet size. Basic strategy is fixed and can be printed on one chart; advanced strategy changes hand by hand with the count.
Can I use advanced strategy online?
Count-based deviations and bet spreads need a shoe that is dealt deep before a shuffle. RNG games reshuffle every hand, most live shoes are cut at around 50%, and some studios use continuous shufflers, so counting online is rarely worthwhile. Composition-dependent plays, worth 0.01% to 0.04%, are the only part of advanced strategy that applies to every online game.