Quick answer: The Illustrious 18 are Don Schlesinger’s high-value Hi-Lo strategy deviations: 18 situations where the true count can justify a different play from ordinary basic strategy. The table below fixes the mislabeled 12 vs. 2 row on the old CountingEdge image and makes the action direction explicit.
On this page
- Illustrious 18 chart: hand, index and action
- How to read an index correctly
- What assumptions are behind the numbers?
- Why these 18 deviations matter
- Why 10,10 vs. 5 and 6 are on the list
- The Illustrious 18 and the Fab Four
- Do not transplant these numbers into another count
- How I would learn the Illustrious 18
- Practical limitations
- Frequently asked questions
- Sources and related CountingEdge guides
The Illustrious 18 are useful because a card counter does not need hundreds of index numbers to capture much of the practical value of count-based playing deviations. They are not a separate counting system, and they are not universal numbers for every count. These thresholds belong to the Hi-Lo framework and should be used with the rule assumptions and true-count method that generated them.
Illustrious 18 chart: hand, index and action
The standard Hi-Lo list below is reproduced in text from the Wizard of Odds Hi-Lo guide, which credits Don Schlesinger for permission to republish the Illustrious 18 from Blackjack Attack.
Decision order: resolve pair splitting and available surrender using the strategy and indices for your game before treating a hard-total row as a hit/stand choice. For example, the 16-vs.-10 row does not tell you to ignore the pair strategy for 8,8 or a correct surrender. Double and split entries require those actions to be available. Use a compatible dealer blackjack-check procedure; do not transplant the chart unchanged into an ENHC game.
| Rank | Player hand / decision | Hi-Lo index | At or above the index | Below the index |
|---|---|---|---|---|
| 1 | Insurance | +3 | Take insurance | Decline insurance |
| 2 | 16 vs. 10 | 0 | Stand | Hit |
| 3 | 15 vs. 10 | +4 | Stand | Hit |
| 4 | 10,10 vs. 5 | +5 | Split | Stand |
| 5 | 10,10 vs. 6 | +4 | Split | Stand |
| 6 | 10 vs. 10 | +4 | Double | Hit |
| 7 | 12 vs. 3 | +2 | Stand | Hit |
| 8 | 12 vs. 2 | +3 | Stand | Hit |
| 9 | 11 vs. A | +1 | Double | Hit |
| 10 | 9 vs. 2 | +1 | Double | Hit |
| 11 | 10 vs. A | +4 | Double | Hit |
| 12 | 9 vs. 7 | +3 | Double | Hit |
| 13 | 16 vs. 9 | +5 | Stand | Hit |
| 14 | 13 vs. 2 | -1 | Stand | Hit |
| 15 | 12 vs. 4 | 0 | Stand | Hit |
| 16 | 12 vs. 5 | -2 | Stand | Hit |
| 17 | 12 vs. 6 | -1 | Stand | Hit |
| 18 | 13 vs. 3 | -2 | Stand | Hit |
The old CountingEdge bitmap mislabeled row 8 as 12 vs. 4 at +3, which duplicated another 12-vs.-4 entry and omitted 12 vs. 2. The correct row is 12 vs. 2 at +3.
How to read an index correctly
An index is a threshold, not a prediction of the next card.
For example:
- 16 vs. 10 at index 0: stand when the Hi-Lo true count is 0 or higher; hit below 0.
- 15 vs. 10 at +4: stand at +4 or higher; hit below +4.
- 10,10 vs. 5 at +5: split at +5 or higher; otherwise keep the 20 and stand.
- 12 vs. 5 at -2: stand at -2 or higher; hit only when the true count falls below -2.
That last example is why negative indices confuse people. Basic strategy already says to stand on 12 vs. 5 under the usual shoe-game assumptions. The deviation occurs only when the count becomes sufficiently negative.
Insurance is separate: take it when the Hi-Lo true count reaches +3 or higher under this reference set.
What assumptions are behind the numbers?
The Illustrious 18 are traditionally presented as Hi-Lo true-count indices. Wizard of Odds notes that the value of learning only these indices was evaluated in a six-deck game, and its accompanying simulation uses a liberal Vegas shoe configuration with dealer standing on soft 17, surrender, double after split, and resplitting.
Do not read that as a claim that every blackjack game has identical thresholds. Exact indices can change with:
- counting system;
- number of decks;
- dealer hits or stands on soft 17;
- surrender availability and timing;
- double and split rules;
- hole-card / peek procedure;
- true-count divisor and deck estimation;
- true-count rounding, flooring or truncation convention.
If you use a generated index set for a specific game, that set takes priority over a generic chart.
Why these 18 deviations matter
Schlesinger’s insight was not that there are only 18 useful deviations. There are many more. The point was that these 18 contribute a disproportionate amount of the practical gain from strategy variation.
Wizard of Odds states that, in its six-deck context, knowing the Illustrious 18 captures roughly 80% to 85% of the value of knowing every index number. That makes the list useful for players who want a compact reference before learning a larger matrix.
The most important decisions tend to combine one or more of these features:
- they occur relatively often;
- the count can materially change the expected value of the decision;
- a larger amount of money may be exposed, as with doubles and splits;
- insurance becomes sensitive to the proportion of ten-value cards remaining.
Why 10,10 vs. 5 and 6 are on the list
Basic strategy normally says stand on 20. Splitting tens is therefore one of the most conspicuous deviations a counter can make.
The Illustrious 18 says:
- split 10,10 vs. 5 at Hi-Lo true count +5 or higher;
- split 10,10 vs. 6 at +4 or higher.
The reason is not that 20 becomes a bad hand. It remains excellent. At sufficiently high counts, however, the density of ten-value cards can make two new hands against a weak dealer more valuable in expectation than preserving the original 20.
That is a mathematical deviation, not a camouflage recommendation. Whether using it is practical in a particular casino is a separate question involving game conditions and countermeasures.
The Illustrious 18 and the Fab Four
The Illustrious 18 do not include the most valuable late-surrender deviations. Schlesinger’s Fab Four are commonly taught alongside them when late surrender is available.
The standard Hi-Lo Fab Four are:
| Player hand | Index | At or above the index |
|---|---|---|
| 14 vs. 10 | +3 | Surrender |
| 15 vs. 10 | 0 | Surrender |
| 15 vs. 9 | +2 | Surrender |
| 15 vs. A | +1 | Surrender |
If the table does not offer late surrender, the Fab Four are irrelevant to that game. See the separate Fab Four blackjack variation guide for the surrender-specific treatment.
Do not transplant these numbers into another count
The decision categories are broadly useful. The numeric thresholds are not portable.
Hi-Opt I, Hi-Opt II, Zen and other systems weight cards differently. A true count of +4 in one system is not necessarily equivalent to +4 in another. This is especially important for ace-neutral counts such as Hi-Opt I and Hi-Opt II.
Use the index table designed for the count you actually use. Our Hi-Opt I guide and Hi-Opt II guide explain why their playing counts and ace-side-count adjustments must remain separate.
How I would learn the Illustrious 18
Do not memorize the table as 18 disconnected facts.
A cleaner progression is:
- Learn insurance +3.
- Add the common stiff-hand deviations: 16 vs. 10, 15 vs. 10, 12 vs. 2/3.
- Add doubles: 10 vs. 10, 10 vs. A, 11 vs. A, 9 vs. 2/7.
- Add the ten splits only after the rest is automatic.
- Learn the negative-index stiff decisions as a group.
- If surrender exists in your game, add the Fab Four separately.
Practice the action in both directions. Knowing “12 vs. 5 = -2” is not enough; you need to know stand at -2 or higher, hit below -2 without stopping to reconstruct the rule.
Practical limitations
The Illustrious 18 only matter when the game lets a meaningful count develop.
They are not useful for ordinary RNG blackjack that effectively starts from a fresh randomized state each round. In live or physical games, you still need:
- a finite shoe or deck;
- observable dealt cards;
- enough penetration for composition information to matter;
- a correct running and true count;
- a strategy chart matching the rules;
- an index set matching the count and true-count convention.
They also do not turn every blackjack game positive. Blackjack payout, table rules, penetration, bet spread, errors, expenses and casino countermeasures can overwhelm the value of a small strategy deviation.
Frequently asked questions
Are the Illustrious 18 a card-counting system?
No. They are playing deviations used with a counting system—most famously Hi-Lo. You still need the count itself, true-count conversion where applicable, basic strategy and a betting plan.
Is 16 vs. 10 really a stand at a true count of 0?
Under the standard Hi-Lo Illustrious 18 reference, yes: stand at 0 or higher and hit below 0. A game-specific generated index can differ, so use the set matched to your rules and convention.
Do the negative indices work backward?
The threshold rule is the same: use the stand/double/split action at or above the index and hit below it. Because basic strategy already stands on hands such as 12 vs. 5, the visible deviation happens when the count falls below the negative threshold.
Can I use the Illustrious 18 with Hi-Opt II?
Not with these numbers. The plays may still be strategically important, but Hi-Opt II requires its own indices because its tags and scale differ.
Sources and related CountingEdge guides
- Wizard of Odds: Introduction to the High-Low Card Counting Strategy — authorized Illustrious 18 and Fab Four reproduction.
- Blackjack Attack by Don Schlesinger — source work cited by Wizard of Odds.
- Hi-Lo card counting
- Basic blackjack strategy
- Blackjack risk of ruin
The Illustrious 18 improves decision quality only when the count, rules and index set are aligned. It does not guarantee a winning session.
