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Blackjack Strategy Guide

Want to know how to win at blackjack? Then before you play blackjack strategy for real money, read our expert guide.

Winning Blackjack Strategies

Our experts are often faced with the question, 'What is the best blackjack strategy?' The truth is that while there are some legitimate ways to play blackjack strategy that can give the player an edge, the vast majority of the systems that purport to do this are completely bogus. In our blackjack guide, you will find notes on some of the systems that can actually gain the player a mathematical advantage when playing online blackjack.

It should be noted that while the blackjack strategies discussed below are legal, the vast majority of casinos will restrict your access to their Blackjack tables/promotions (if not outright ban you from their casino) if they think that you’re applying them. For this reason, we recommend employing any blackjack strategy with caution.


Please be aware that the following strategies are only valid where the game being played is not shuffled after every hand, or depend on a weak dealer providing the players more information than they should have. As such they cannot gain an advantage where the player is using Random Number Generator (RNG) games – the computerized versions of Blackjack found at online casinos. There are live casino games available online where some of the techniques described below may be applicable, but in my opinion the game conditions available online are not conducive to gaining any sustainable level of advantage.

Regarding the legality of Card Counting and Shuffle Tracking– the best blackjack strategies discussed below are legal within the US and UK as long the player can perform them without use of external aids (computers/calculators). The moment that a computer is used to keep track of the cards or perform calculations, this becomes a violation of gaming law. We strongly discourage anyone from engaging in any form of illegal activity.

Card Counting

The fundamental premise behind Card Counting is that high cards benefit the player while low cards benefit the dealer. There are several reasons for this;

- Where a Blackjack is dealt, which consists of two high cards, if the player receives the Blackjack they win 1.5x their bet while if the dealer has Blackjack they only receive the player’s bets. Therefore, if the player and the dealer alternated in receiving Blackjacks, the player would win an additional half bet for every 2 hands played.

- Where the player doubles their bet, most often when they hold a 9, 10 or 11, a ten value benefits the player, creating a strong hand with 2 bets out.

- As the dealer is forced to draw cards to a total of 17, where the player can choose to stand on any total, ten value cards will bust the dealer far more often than they’ll bust the player. This is also the reason that low cards benefit the dealer more than the players.

There are other reasons high value cards benefit the player, but the above are the strongest factors. As such if the player knows that there are more high cards than low cards left to be in the deck – depending on the rules and the number of extra high cards – the player can have the advantage over the house.

The most basic form of Card Counting is the HiLo system. The HiLo count assigns a value to the cards as follows;

2, 3, 4, 5, 6       +1

7, 8, 9         0

10, Jack, Queen, King and Ace         -1

The player starts their count at 0 and as each card is played out adjusts the total according to the values displayed above. This is referred to as the Running Count. If a positive count results this means that more high cards remain to be played and the player may have an advantage. The higher the count the strong the advantage the player has.

Having more than one deck in play does not make Card Counting substantially more difficult but it does mean that adjustments have to be made to the count. For obvious reasons having a Running Count of +5 is substantially more significant if there is only one deck remaining to be played than if there are 6 decks still to play.

For this reason, to gain an accurate assessment of the value of the cards remaining to be played to the player the Running Count needs to be divided by the number of decks remaining to be played. This figure is referred to as the True Count.

For example;

If the Running Count is +12 and there are 3 decks remaining, you would divide 12 by 3 which gives us a True Count of +4 (meaning there are 4 extra high cards for every deck remaining to be played).

As an approximation each point increase in the True Count shifts the House Edge 0.5% towards the player. I stress that this is not a precise figure and as the player who plays perfect Basic Strategy is generally starting with a disadvantage of around 0.5% or a little more, but this is just an approximation and vary with many different factors. As such the casino will normally have the edge over the player at any True Count less than 2.

On average - and depending on the rules number of decks in play, number of decks dealt out before the shuffle and bet spread (difference between the highest and lowest bet) – Card Counting can provide the player of an edge between 0.5-2% over the house.

The above is a very simplified overview of Card Counting. So, can you really learn how to win at blackjack? To successfully gain an advantage over the casino using Card Counting strategies requires a lot of practice and research and much of the detail and information required to win is absent from this discussion, including the effect of different game rules, changes to Basic Strategy where the composition of the remaining deck has changed, depth of shuffle point (penetration) and risk and bankroll considerations. Where time allows I may cover this topic in more depth at a later date.

Shuffle Tracking

There are several forms of Shuffle Tracking but the primary concept – as the name suggests – involves the player tracking cards through the dealer’s shuffle. In general the player will play through one complete deal of the pack, knowing the shuffle that will be performed in advance, and attempt to locate either a dense packet of high cards, a dense packet of low cards or a specific favourable card (usually an Ace) to visually follow through the shuffle.

Where a packet of high cards is followed the player will attempt to position them in a favourable place in the following shoe by using the cut card – often at the very start of the shoe, allowing them to draw a sharp distinction between their play and that of a Card Counter, who will normally place their large bets toward the end of the shoe - and will raise their bets substantially to take advantage of the higher than normal density of player favourable cards.

Where a packet of low cards is followed the player will attempt to use the cut card to remove these dealer favourable cards from play and adjust their playing and betting strategy for the subsequent shoe accordingly.

Where an Ace is followed through the shuffle – normally using cards that were directly adjacent to it in the previous shoe to indicate when the Ace is likely to appear – the player will attempt to steer this card to their hand providing that hand with a substantially improved chance of being dealt a Blackjack.

Shuffle Tracking can provide the player with a substantially larger advantage than those achievable with Card Counting – often double or more - but is vastly more difficult to perform successfully and far more costly where mistakes are made. As such only the most skilled players will ever make money employing Shuffle Tracking techniques.

Regarding the legality of Card Counting and Shuffle Tracking– is you want to play with blackjack strategy, it is are legal within the US and UK as long the player can perform them without use of external aids (computers/calculators). The moment that a computer is used to keep track of the cards or perform calculations, this becomes a violation of gaming law. We strongly discourage anyone from engaging in any form of illegal activity.

Hole Carding

Hole Carding is the practice of locating a dealer that is insufficiently protecting their down card (hole card) enough so that a vigilant player can gain information regarding what the card is. The player then uses this information to adjust their strategy to account for the additional information.

Hole Carding was first discussed publicly by Blackjack author and Hall of Fame inductee Ken Uston in his book ‘Million Dollar Blackjack’. Depending on the quality and frequency of the Hole Card information available to the player it is possible to gain an advantage of up to 13% with perfect information on every hand and the correct playing strategy.

Card Steering

Another method of gaining an advantage over the house in the game of Blackjack is observing an exposed card during the shuffle/dealing procedure that should not have been visible. The easiest card to gain information about is the bottom card on the pack prior to the player cutting the deck after the shuffle, though this is far from the only way to gain this type of information and sloppy dealers and defective equipment can provide just as strong opportunities. If a card’s location and rank can be identified the card can be “steered” into a position that’s favourable to the player. This would generally be to the dealer’s hole card if the card is small or to the player’s hand if the card is a ten or Ace, though ten cards can potentially be steered into double down opportunities or as the dealer’s hit card in the hopes of busting the dealer’s hand.

Regarding the legality of Hole Card play and Card Steering – These strategies are only legal within the US and UK if the player can gain the required information from a natural position and without use of devices at the table they are playing at. If the player has to use reflective devices, cameras or accomplices off table to gain the necessary information to perform these techniques they’ve crossed the line of legality.


There are several methods of legitimately gaining an advantage via online blackjack strategy. By and large these involve the use of promotions, bonuses and comp point systems and the games by themselves – assuming the game is functioning in a correct fashion – will not provide any additional information about the cards and shuffle after every hand.

It should be noted that online advantage play is not specific to Blackjack and in recent years the wagering requirements for player’s choosing to play only Blackjack has inflated to the point that Blackjack is now often a sub-optimal choice for the player.

Blackjack Strategy Origins

Basic Strategy is the mathematically correct way to play every possible hand that can occur at the Blackjack tables and was first published in 1956 by four American mathematicians, Roger Baldwin, Wilbert Cantey, Herbert Maisel and James McDermott, who later came to be known as ‘The Four Horsemen of Aberdeen’. Their work was first published in the ‘Journal of the American Statistical Association’ in 1956 and later republished as a book ‘Playing Blackjack to Win’ in 1957. The true importance of their work didn’t become apparent until later, but is one of the most significant factors in the growth of what is now considered to be the most successful table game in the vast majority of land-based and online casinos around the world.

What is so impressive about the work of Baldwin, Cantey, Maisel and McDermott is that they completed their analysis simply by playing the game, recording the results and crunching the numbers on an old calculator. Today this sort of analysis would be far less demanding, with simulations completed at the touch of a button, but the hard work of the Horsemen changed the game of Blackjack forever.

It should be noted that each rule variation in the game of Blackjack results in a different Basic Strategy, but this will be addressed below in the Basic Strategy section of this article.

Card Counting

In 1962 Edward O Thorp, a mathematics professor who has worked at some of the most respected universities in the United States, read the work of Baldwin, Cantey, Maisel and McDermott on Basic Strategy in Blackjack and concluded that each card in the deck must have an inherent value to the player, either positive or negative, and that if the cards that had been played already could be accounted for the player would know whether the cards still to be dealt were favourable to the player or the dealer.

After extensive research Thorp concluded that small cards benefited the dealer and high cards (ten pips and face cards) benefited the player. So an excess of high cards left to come out would create a situation where the player would have the advantage over the casino. While over the average of all hands the casino would still have an advantage, if the player bet low when the odds favoured the house and high when the odds favoured themselves that advantage could not only be nullified but turned towards the player.

This revelation lead to the development of the first Card Counting system and the publication of Thorp’s book ‘Beat the Dealer: A Winning Strategy for the Game of Twenty One’ which was massively successful, selling over 700000 copies and entering the New York Times Best Seller List.

The publication of ‘Beat the Dealer’ quickly transformed the game of Blackjack into the most popular and profitable game in the casinos (this has since been eclipsed by online slots games). The surge in popularity was directly related to players realising that the game of Blackjack could be beaten. The reality however was that the vast majority of players failed to learn the skills necessary to beat the game so the publication of a winning system actually resulted in an increase in profits for the casinos.

The Ten Count was an awkward system to implement accurately, requiring the player to keep note of how many high cards came out, how many low cards came out and then calculate the ratio of remaining high to low cards in their head. While awkward this was still achievable for a patient practitioner at a single deck game.

By 1964 the ‘Ten Count’ that Thorp published had been accepted to be the first legitimate winning gambling system and so many players had read ‘Beat the Dealer’ that the casinos in Las Vegas – lead by the ‘Las Vegas Resort Hotel Association’ (LVRHA) and fearing substantial damage to their bottom line – made substantial changes to the standard rules used at the Blackjack tables in the casinos they represented. A spokesperson for the LVRHA, Gabriel Vogliatti gave the following quote to the media;

“In the last 15 years there hasn’t been one plane landed without at least one person in possession of a system. This guy [Thorp] is the first in Las Vegas history to have a system that works.”

The specific rule changes that were implemented were a restriction of the splitting of Aces and only allowing the player to double down on hard eleven. These rule changes had the opposite of the desired effect – skilled players could still beat the games despite the poorer rules and the unskilled players deserted the casinos offering the poorer rules. Even the additional edge that the rule provided the house was not enough to compensate for the substantial loss of custom resulting from the rule changes.

Within two weeks of the new rules being implemented, the financial consequences for the casinos had been so substantial that the rules were returned to their former standards with one slight exception, the casinos started to increase the number of decks used to play the game figuring that it would be more difficult to keep track of more cards. This strategy failed to be the magic bullet that the casinos were looking for to stop Card Counting and Thorp quickly released a second edition of ‘Beat the Dealer’ which included the first balanced Card Counting system, devised by Julien Braun, since named the HiLo count.

The HiLo count assigned a point value to each card which the player would then add or subtract for each card seen, reducing the mental workload for the player substantially by allowing the use of the system with only one memorised number. The HiLo count made the addition of multiple decks a relatively minor inconvenience to the Card Counter.

Card Counting changed the game of Blackjack forever -- from a table game that was generally considered to be a wife’s game while her husband was at the Craps tables -- to the number one table game in the world. Its impact on the world of casino games has been unquestionable.

Reductions in Blackjack Payouts

More recently – in the early 2000’s – offline casinos started to reduce the payouts offered on their Blackjack tables primarily on their single deck games. This was done in such a way that many players did not realise that they were being offered a weaker game. The casinos dropped the payout for a player receiving a Blackjack from 3:2 to 6:5. With this rule the casinos finally found a way to substantially increase their edge over the playing public without discouraging players. The larger numbers in the ratio lead the unwitting player to believe that the 6:5 payout is better but if the player is wagering $100/hand they would receive $150 for receiving a Blackjack on a 3:2 game and only $120 for the same hand on a 6:5 game.  Even wagering only $10/hand the player will still lose $3 for every Blackjack they receive if they are sitting at a 6:5 table.

As the player will receive a Blackjack approximately every 21 hands, even at a slowly dealt game the cost of this reduction can add up very quickly. This rule is now being added by several smaller software providers – generally on single deck games - to online casinos. These games are by no means prolific, but their appearance is no good thing for players.

The correct response to seeing a Blackjack table that only pays 6:5 is to walk away from the table or close the game!

Basic Strategy Rule Variations

Basic Strategy is the mathematically optimal way to play any possible hand in the game of Blackjack. Many rule variations in the game can impact the Basic Strategy that the player should apply to that game. While Basic Strategy does not ensure that you’ll win every hand, it ensures that over the mathematical long run you will lose the least amount possible.

As part of our blackjack guide, our experts have compiled a Basic Strategy table. Directly below you will find a table for one of the more common rule variations (6 decks, Resplit to 4 Hands, Double After Split, Dealer Stands on Soft 17, Late Surrender).

To use the table, compare the hand that you’ve been dealt to the column on the far left. Once you’ve found the appropriate hand follow that row along until you find the dealer’s up card at the very top row of the table. The corresponding cell in the table defines the action that the player should take.

Player's Hand Dealer's Upcard
66P P P P P HH
77P P P P P P H
CodeBest Play
DDouble else Hit
DsDouble else Stand
RSurrender else Hit
RsSurrender else Stand

Rule Variations and House Edge

As a rough guide here is a list of rule variations and the approximate effect (based on the rule set displayed above) they will have on the House Edge of a Blackjack game;

1 Deck +0.51%
2 Decks +0.20%
4 Decks +0.05%
5 Decks +0.02%
8 Decks -0.02%
Blackjack pays 2 to 1 +2.06%
Blackjack pays 6 to 5 -1.20%
Blackjack pays 1 to 1 -2.01%
Suited Blackjack pays 2 to 1 +0.50%
Early Surrender (full) +0.56%
Early Surrender (against a 10) +0.21%
Late Surrender +0.07%
5 Card Charlie automatic winner +1.28%
6 Card Charlie automatic winner +0.14%
7 Card Charlie automatic winner +0.01%
5 card 21 pays 2 to 1 +0.17%
5+ card 21 pays 2 to 1 +0.21
777 pays 3 to 1 +0.06%
Not allowed to split 4s -0.00%
Draw to Split Aces +0.17%
Resplit to 3 +0.04%
Resplit to 4 +0.05%
Resplit Aces (Resplit to 3 hands) +0.09%
Resplit Aces (Resplit to 4 hands) +0.11%
No peek for Blackjack -0.10%
No peek on Ace -0.09%
No peek on 10 -0.01%
No peek with doubles/splits returned on Blackjack -0.02%
Double Hard 9-11 only -0.09%
Double Hard 10-11 only -0.18%
No Double after Splits -0.11%
No splitting aces -0.16%
Hit Soft 17 -0.18%
Player loses ties
Player loses 17 ties
Player loses 17,18 ties
Player loses 17,18,19 ties
Player loses 17, 18, 19, 20 ties
Dealer 22 pushes all hands
Dealer 22 pushes all hands except Blackjack