Card counting isn’t just about betting more when the count is high. The most successful counters also deviate from basic strategy based on the count, capturing additional edge through smarter playing decisions.

The “Illustrious 18” is a list compiled by blackjack expert Don Schlesinger that identifies the 18 most valuable strategy deviations. Mastering these plays can add approximately 0.1-0.2% to your overall edge.

The Complete Illustrious 18

Here are the deviations, listed in order of importance:

1. Insurance: Take insurance at True Count +3 or higher
2. 16 vs 10: Stand at TC 0 or higher (normally hit)
3. 15 vs 10: Stand at TC +4 or higher
4. 10,10 vs 5: Split at TC +5 or higher
5. 10,10 vs 6: Split at TC +4 or higher
6. 10 vs 10: Double at TC +4 or higher
7. 12 vs 3: Stand at TC +2 or higher
8. 12 vs 2: Stand at TC +3 or higher
9. 11 vs A: Double at TC +1 or higher
10. 9 vs 2: Double at TC +1 or higher
11. 10 vs A: Double at TC +4 or higher
12. 9 vs 7: Double at TC +3 or higher
13. 16 vs 9: Stand at TC +5 or higher
14. 13 vs 2: Stand at TC -1 or higher
15. 12 vs 4: Stand at TC 0 or higher
16. 12 vs 5: Hit at TC -2 or lower
17. 12 vs 6: Hit at TC -1 or lower
18. 13 vs 3: Hit at TC -2 or lower

Why These Matter

Insurance is by far the most valuable deviation. A standard insurance bet is a sucker play with a house edge over 7%. But when the true count reaches +3, insurance becomes profitable because the increased density of tens makes dealer blackjack more likely.

The standing deviations (16 vs 10, 15 vs 10) capture value by recognizing that a high count means more bust cards in the deck for the dealer.

Practical Application

Don’t try to memorize all 18 at once. Start with the top 5, which capture most of the value. Add more as your counting becomes automatic.

Practice these deviations in our trainer before trying them in a casino. Making obvious deviation plays can also attract attention, so consider whether the EV gain is worth the heat.

Practice Deviations