The Ace/5 Card Counting System

Fundamentals
Advantages and Disadvantages

Written by Boris Atanasov

With more than 4+ years of experience in the iGaming industry, Boris Atanasov writes exciting content about slots, video poker, roulette and blackjack.

, | Updated: September 25, 2025

There are more than a dozen professional card-counting strategies, but blackjack players often avoid them because of their complexity and the risk of being detected by the pit boss. The Ace/5 Count, however, allows card counters to remain hidden while still gaining a small edge over the casino.

The Ace/5 system for counting cards was popularized by renowned mathematician and game researcher Michael Shackleford. Shackleford, also known as the Wizard of Odds, is a blackjack and poker player. Along with this counting system, he has developed various gaming strategies as well as mathematical analyses of numerous casino games. The Ace/5 Count, according to him, is currently the easiest counting system players can find because it only requires them to track 5s and Aces.

This blackjack card-counting method simplifies the fundamental principles, reducing complex systems to a straightforward tactic that is perfectly manageable even for beginner-level players. However, like every card-counting system ever created, it does have its limitations.

Basics of the Ace/5 System

How to Use the Ace/5 System?

Basics of the Ace/5 System

Unlike most methods used by professional card counters, the Ace/5 Count does not track every card in the deck. The beauty of this system lies in its simple structure – it assigns numerical values only to 5s and Aces, hence the name. Aces are assigned the value of -1, while 5s are worth +1. All other cards are neutral.

The Ace/5 is a balanced system, which means that the sum of all numerical values is 0 and the count starts at 0. When practicing the Ace/5 at home, players who correctly count down to the last card in the deck will finish with a final count of 0. Because the only values used here are +/-1, we can say that this is a level-1 system, and players simply add or subtract 1 as cards are dealt at the table.

Some blackjack players may wonder why 5s and Aces in particular are chosen. The idea is to count only the “best” and the “worst” cards in the deck instead of tracking every card and maintaining a running count at all times. Aces are considered the most favorable cards for the player, whereas 5s are mathematically proven to offer the worst odds.

As Shackleford explains, this system was designed for 6- and 8-deck games. It is most effective on games that follow the liberal Las Vegas Strip Rules. Here, blackjacks pay 3:2 and penetration is 75% or higher. The dealer stands on soft 17, and players may double after a split. They can resplit Aces, and late surrender is allowed. The system is also effective in 4-deck games. If the dealer hits on soft 17, however, the player will lose a mathematical advantage of 0.22%

How to Use the Ace/5 System?

The Ace/5 System can be learned very quickly and applied in casinos by both professional and recreational players. As with all counting methods, it begins with a fresh shoe or after a reshuffle. Because this is a balanced system with an initial running count of 0, players begin by placing their minimum bet. Whenever a 5 appears on the table, they add 1 to their running count; when they see an Ace, they subtract 1. All other cards have a value of 0, so they do not affect the running count.

The pivot for this system is +2, which means that when the running count reaches 2, players should increase their bet. The higher the count, the greater the stakes should be. When the count falls to +1 or less (+1, 0, -1, etc.), players return to the minimum bet. For better efficiency, it is recommended that players double their bet at +2 – each time the count rises, the stakes should be doubled. However, it is wiser to double only after a win, which helps avoid suspicion that the increase is tied to the count.

Players may use any betting spread, but a good option is to choose 1-8, 1-16, or 1-32. A larger spread increases the player’s advantage over the casino because more money is wagered when the shoe is favorable. Even so, the edge obtainable with this system is still quite small – less than 1%. This implies higher risk and greater variance compared with more advanced systems.

Let’s examine how the betting spread affects the player’s advantage. When the count rises to +2, the player bets 2 units; at +3, they bet 4 units; at +4, they bet 8 units. This is a low betting spread that is safe but not particularly profitable, especially for players who want to avoid drawing attention as card counters. In this scenario, the player doubles their bets only after a winning round, creating the impression of increasing stakes during a “winning streak”.

Betting Spread	Player Advantage
01/08/19	0.30%
1-16	0.45%
1-32	0.57%

Advantages

Disadvantages

The Ace/5 Count described by Michael Shackleford (and others) comes with many advantages over the majority of systems for card counting. First and foremost, it is simple and comprehensible as it focuses only on 2 cards and does not have a side count. Players do not need to convert the running count into a true count, which could be particularly tricky in games that use 6 or 8 decks of cards.

This system has two obvious weaknesses that should be taken into consideration. The simplicity of the Ace/5 Count is clearly reflected in its potential for bringing profits. Even when playing under liberal rules and following basic strategy for every decision in the game, players would not be able to gain a substantial advantage over the casino. This means that even those who are applying the system perfectly would be at risk of losing their bankroll.

Moreover, this system works best with 6 or 8-deck games but it can also be used with relative success in 4-deck variations of blackjack. Nowadays, casinos usually use 6 or 8 decks of cards for blackjack so the Ace/5 System would be perfect. It is also probably the best option for those who are new to card counting. Before considering popular methods such as the Hi-Lo or KO Count, novices should try the Ace/5 and see how well they would manage their betting – as this is one of the most important things in card counting.

The Ace/5 System also has a noticeable limitation – it is not only devised for multi-deck shoe games but also for a certain set of rules that are quite liberal and rare. For many players, who are new at card counting, this method will simply be ineffective. Many of them would be able to break even in their blackjack sessions and some of them would not be able to reduce the house edge at all.

Last, but not least, this system deals with another huge issue – casinos and their ability to recognize the betting patterns and specific playing decisions of card counters. When used carefully, the Ace/5 Count allows for a wonderful “camouflage” betting, a style of betting that conceals card counters.

Simplified and easy to learn, the Ace/5 System for counting cards is suitable for all types of players, including complete novices who find tracking every card on the table too difficult or confusing. When using this method, they do not need to worry about complex concepts such as true count, pivot points, or initial running counts. Moreover, they are less likely to be detected immediately by the casino, and although the Ace/5 Count may not win them a fortune, it can still deliver a profit over the long term.

The Ace/5 Card Counting System

The Ace/5 Card Counting System Fundamentals

Basics of the Ace/5 System

How to Use the Ace/5 System?

Advantages and Disadvantages of the Ace/5 System