The Illustrious 18

Written by Dean McHugh
Dean McHugh
Dean McHugh is a full-time writer with more than 20 years of experience in the iGaming industry. Specialising in casino reviews, slot analyses, and sportsbook evaluations, he delivers clear, engaging, and insightful content for both industry professionals and casual players. Over the past four years, he has contributed extensively to leading iGaming comparison websites.
, | Updated: Fri 29 August 2025

Card counting systems have grown significantly in popularity in recent years, which is why many strategies of this kind have been developed and refined to meet players’ needs. In general, these systems are considered more advanced, as they require greater concentration, effort and time.

They can be extremely beneficial only if they are applied correctly throughout the game; however, this can be a very challenging task, as casinos are full of distractions. It is no secret that card-counting systems work best in combination with basic strategy, which is why players shouldn’t attempt to use them if they lack the necessary knowledge.

Importance of Altering the Basic Strategy

The basic strategy enables players to make the best possible bets and moves in any given situation, taking into account the dealer’s upcard and the total of their own hand. Card counting gives players valuable information about the ratio between high- and low-value cards, which in some cases requires altering the basic strategy, as its suggested moves are not always the most beneficial.

This is why they should be ready to adjust it according to the true count of their chosen system, as this is the only way they will be able to take advantage of its accuracy and efficiency.

In this sense, if players are to alter their betting and playing decisions during the game, they still need to be prepared beforehand for these possible changes. It is true that to recall the basic strategy and keep track of the cards simultaneously is very challenging, and having to remember additional variations can make the task even harder.

However, players need to understand that it is essential for them to be flexible and adjust their bets according to the particular situation, as this is the only way they can make the most of it. This is why the term “index number” was created; it shows which move is optimal in a particular case from a mathematical point of view.

Basic Strategy Chart
Players’ HandDealer’s Up Card
2345678910Ace
8HHHDDHHHHH
9HDDDDHHHHH
10DDDDDDDDHH
11DDDDDDDDDD
12HHSSSHHHHH
13SSSSSHHHHH
14SSSSSHHHHH
15SSSSSHHHHH
16SSSSSHHHHH
A-2HHHDDHHHHH
A-3HHDDDHHHHH
A-4HHDDDHHHHH
A-5DHDDDHHHHH
A-6HDDDDHHHHH
A-7SDDDDSSHHH
A-8SSSSDSSSSS
A-9SSSSSSSSSS
Ace-AceSPSPSPSPSPSPSPSPSPSP
2-2SPSPSPSPSPSPHHHH
3-3SPSPSPSPSPSPHHHH
4-4HHHSPSPHHHHH
5-5DDDDDDDDHH
6-6SPSPSPSPSPHHHHH
7-7SPSPSPSPSPSPHHSH
8-8SPSPSPSPSPSPSPSPSPSP
9-9SPSPSPSPSPSSPSPSS
H = Hit, D = Double Down, S = Stand, SP = Split

What is the Illustrious 18

Card counters need to take several important factors into account if they want to make the best possible move and bet in every situation. It is essential to know the chosen system, in addition to basic strategy, backwards and forwards so that they can apply them when needed. Also, players should understand how to use the true count, as it tells them whether it is better to increase or decrease their bets.

However, as already mentioned, there are some situations in which the best move is based on the true count as well as on the index number. The Illustrious 18 comprise eighteen highly efficient variations of basic strategy devised by Don Schlesinger.

The reason why they have become so popular is that, thanks to them, players can make the most of every hand by altering the basic strategy accordingly and taking into account the valuable information the card-counting system provides. The index numbers of his chart play a crucial role, and if players want to take advantage of these variations, they need to understand them fully.

How the Illustrious 18 Work

The Illustrious 18 were developed to improve the expected return based on the moves players make. Just like any other strategy, players need to take their time to memorise the index numbers, the moves suggested by the chart and, of course, the situations in which they should be used. Even though these variations add more information to remember, they give players a very good chance of winning and making a profit.

This way, they will be able to make the most of each system and apply the valuable information it provides in the best possible manner. Players need to understand that every subtlety can make the difference between winning and losing a particular hand. One very important factor to take into account is the number of decks in play, as this also requires players to adjust their strategy to some extent.

‘Illustrious 18” Hi-Lo Card Counting Indices
RankHandIndexDecision
1Insurance3Take
216 vs. T0Hit/Stand
315 vs. T4Hit/Stand
4T-T vs. 55Stand/Split
5T-T vs. 64Stand/Split
610 vs. T4Hit/Double
712 vs. 32Hit/Stand
812 vs. 43Hit/Stand
911 vs. A1Hit/Double
109 vs. 21Hit/Double
1110 vs. A4Hit/Double
129 vs. 73Hit/Double
1316 vs. 95Hit/Stand
1413 vs. 2-1Hit/Stand
1512 vs. 40Hit/Stand
1612 vs. 5-2Hit/Stand
1712 vs. 6-1Hit/Stand
1813 vs. 3-2Hit/Stand

About the Creator of the Illustrious 18

Donald Schlesinger is a successful author and a prominent mathematician who is a member of the Blackjack Hall of Fame. His works are read by many players worldwide because they have proven to be both beneficial and engaging.

One of his best books is Blackjack Attack – Playing the Pros’ Way, as it covers both theory and practical application; his observations are well worth reading. Mr Schlesinger is best known for establishing the Illustrious 18, as these play variations have become an inseparable part of every card counter’s strategy.

What is the “Fab Four”

As explained above, the Illustrious 18 are variations of the optimal strategy. To make things even more beneficial to players, Don Schlesinger introduced the so-called Fab Four. It describes the best surrender actions based on the Hi-Lo card-counting system. Below, we list the situations in which you should surrender according to the Fab Four:

  • The player’s hand is 15, the dealer’s upcard is 9, and the true count is +3
  • The player’s hand is 15, the dealer’s upcard is 10, and the true count is 0
  • The player’s hand is 15, the dealer’s upcard is an ace, and the true count is either +2 (in S17) or -1 (in H17)
  • The player’s hand is 14, the dealer’s upcard is 10, and the true count amounts to +4

Conclusion

Card-counting systems are renowned for their accuracy and efficiency, which is why many advanced players rely on them. If applied alongside basic strategy, they can be extremely beneficial, giving players the opportunity to gain an advantage over the casino.

There are, however, a number of other factors that should be taken into account, as they also play a crucial role in a player’s performance. It is true that both strategies work very well together; nevertheless, card counting provides blackjack fans with valuable information about the upcoming cards, which can be used to make even better decisions about their bets and moves.

The moves suggested by basic strategy are based on the assumption that players do not know what the upcoming cards will be. Card-counting systems are designed to provide such information, which is why basic strategy should be adjusted accordingly; in this way, the player’s edge will be significantly increased. Also, if blackjack fans want to succeed, they need to be very disciplined and organised in order to apply the systems effectively in a casino setting.