The practice of how to count cards requires a fair amount of concentration, but is easier than its name implies: a player must observe the cards as they are dealt, keep track of a running total, and adjust the wager accordingly.
Card counting is, as the name indicates, a technique of counting the cards that have already been dealt to have an estimation, by their absence, of those that remain to be dealt from the deck. Various systems have been developed for counting cards, none of which require a photographic memory or a genius IQ. That being said its still a blackjack advanced strategy. All a player needs do is to keep track of a running total that reflects whether the remainder of the shoe is favourable, by a relatively simple system that’s accessible to a person of average intelligence. That running total, or “count,” leads the player to increase his bets when the deck is in his favor and decrease them (or leave the game) when it is in favour of the house.
Is Card Counting Illegal?
The practice of card counting is discouraged by casinos, which have succeeded in casting the practice in a negative light to the point that many players erroneously believe that it is illegal. Where it is permissible for casinos to do so, they will gladly eject a player who counts cards (or ban card counters altogether). However, this is all a marketing campaign on the part of the casinos to discourage players from making the smart bet. Simply stated, card counting is NOT ILLEGAL, nor can it fairly be considered a form of cheating.
Cheating is, by definition, an intrusion that offsets the odds. A cheater may cooperate with the dealer, alter equipment, use sleight of hand to increase his wager or switch his cards after the deal, or in other ways actively alter the situation or circumvent the rules to force the odds in his favour. The card counter, meanwhile, merely observes phenomena that are visible to anyone at the table under normal circumstances. When the natural course of events happens to turn in his favour, he makes the best of it. This does not violate the rules of the game or alter the situation at all, any more than a sports bettor who considers the past performance of a team before placing a wager for or against them.
Neither does card counting guarantee a victory. Even in situations where the deck seems to favour the player by a wide margin, the order and value of the cards remain random. Regardless of the “weight” of the deck, the cards will fall as they may. There is a higher likelihood of winning in some situations, and the card counter will increase his wager accordingly—but the possibility of losing always remains.
For these reasons, casinos have been unsuccessful in their attempts to lobby for legislation or win court cases against card counters. The practice remains completely legal. In locations where a casino is permitted to refuse service to anyone, card counters are actively pursued, expelled, and banned from the premises. Simply put, the house does not want to serve the gambler who stands a good, or even fair, chance of winning.
How To Count Cards In Blackjack
It is not necessary, as some assume, to keep track of every card that has been dealt. Though it would be useful to know the exact number of each value that remain, it is not necessary and beyond the capabilities of the average (or even reasonably intelligent) player to do so. The blackjack card counting strategy relies on an estimate of the value of the cards that have been dealt, as an indication of the ones that remain to be dealt.
This tutorial is based on the HighLow counting system: two, three, four, five, and six cards are valued at +1; seven, eight, and nine are 0; and all tenvalue cards and aces are valued at 1. Other counting systems are available (discussed in alternate counting systems), but the HighLow system is one of the easiest to follow, and sufficiently effective in practice.
By this system, and others, low cards “add” to the count and high cards “subtract” from it. This is because the removal of low cards from the deck increases the number of high cards left to be dealt, and vice versa – and a higher proportion of high cards in the deck favour the player.
Learning How To Count Cards
To keep the count, a player must note the cards as they are dealt, and keep a running total in mind. One method of doing this is by noting the value of each card as it is overturned and keeping a constant tally of the total:
CARD:  K  6  9  4  6  5  4  7  Q 

VALUE:  1  +1  0  +1  +1  +1  +1  0  1 
TOTAL:  1  0  0  +1  +2  +3  +4  +4  +3 
While this is effective as a training method, the resulting physical behaviors—constant eye and head movement during the deal—is a very obvious signal to casino personnel (dealer, pit boss, surveillance crew) that the player is a card counter.
A better technique is to observe the value of each hand as it is played, as it is common for even leisure players to watch as others play their hands, noting the total value as a player’s cards are collected:
Player 1  K  9  1  

Player 2  6  5  7  +3  
Player 3  2  J  4  8  +1 
Player 4  A  3  4  +1  
Dealer  Q  8  2  
TOTAL:  +2 
Using this technique will allow the player to focus on other things while the cards are being dealt—namely, acting the part of the leisure player in order to avoid detection. A hand of two high cards has a net effect of 2, two low hit with a high +1, a high and a low hit with a high 1, a blackjack is 2, etc. It requires a bit more practice to learn to count cards a hand at a time rather than onebyone—but it will eventually become second nature, so the effort spent to learn this technique will result in less effort to use it in an actual playing situation.
How To Count Cards With Multiple Decks
Because the count is an estimation of the proportion of high cards left in the deck, it must be adjusted according to the number of decks that are used in the game. The running count keeps track of the instances—the number of high cards, as opposed to low ones, that remain in the deck. In other words, if four kings are dealt from a single deck, none remain—but if four are dealt in a doubledeck game, four remain.
The easiest way to estimate the “true” count from the running count is to divide the running tally by the number of decks in the game. A count of +8 is worth +8 in a singledeck game (8/1), but only +4 in a twodeck game (8/2), +2 in a fourdeck game (8/4), and +1 in an eightdeck game (8/8).
A more accurate method to estimate the “true” count requires dividing the running count by the number of decks that remain to be played. If the running tally is +15 in an eightdeck game, but two decks have already been played, the correct count would be +2.5 (+15 divided by six remaining decks), and +5 (+15 divided by three remaining decks), when five decks have been played. Though the running count of instances remains the same, there proportion of higher concentration of high cards increases in a smaller deck. Again, four kings among 156 cards are more likely to show than four kings among 312 cards.
Estimating the number of decks is relatively simple to do in most casinos: glance at the discard tray. Most casino decks are almost exactly half an inch thick—so if the discard stack is about 1.5 inches tall, three decks have been dealt, and only five remain in an eightdeck game.
If the casino uses an opaque discard rack, and if you cannot sit in a position that allows you to see the stack of discards (first base is an excellent position for to be able to see the discard stack), you may have to estimate by the number of players and rounds played. Since the average hand requires 3.2 cards, a game with five hands in play (four players plus the dealer’s hands) will consume 16 cards per round—roughly one deck every three rounds played.
Single Deck Blackjack Card Counting
As an example of how the absence of cards alters the odds in the remaining deck, take this example of a single deck blackjack game in which seven players are present. In the first hand:The dealer’s upcard is a queen.

 The first player draws sixfive, doubles down and draws an eight.
 The second player draws ninefive, hits and draws an ace, hits again and draws a seven, busting the hand.
 The third player is dealt a pair of aces. He splits them and draws a four and a six.
 The fourth player draws a five and an eight, hits and draws a three, hits again and draws an eight, busting.
 The fifth draws a pair of fours, hits and draws a six, hits again and draws a four, standing on 20.
 The sixth player draws a nine and an eight, stands on hard 17.
 The last player draws two jacks and stands on 20.
 The dealer turns over his hole card, a two, and hits twice, drawing threes, to stand on an 18.
After this hand is played, these cards are moved to the discard rack and the next hand is dealt with a partial deck. In the deck that remains, there are three twos; one of each three, five, and six; three sevens; two nines, fifteen tenvalue cards (ten, jack, queen, king), and a single ace. In other terms, there are only six low cards (two through six) and eighteen high cards (nine, ten, ace) left, along with three sevens (which are neutral by most systems). The “count,” according to a common card counting system (HighLow) is +8, meaning that the deck is skewed heavily in favor of the players.
ORIGINAL  

VAL  #  % 
4  1  0.59% 
5  2  1.18% 
6  3  1.78% 
7  4  2.37% 
8  5  2.96% 
9  6  3.55% 
10  7  4.14% 
11  8  4.73% 
12  15  8.88% 
13  14  8.28% 
14  13  7.69% 
15  12  7.10% 
16  11  6.51% 
17  10  5.92% 
18  9  5.33% 
19  8  4.73% 
20  16  9.47% 
S12  1  0.59% 
S13  2  1.18% 
S14  2  1.18% 
S15  2  1.18% 
S16  2  1.18% 
S17  2  1.18% 
S18  2  1.18% 
S19  2  1.18% 
S20  2  1.18% 
21  8  4.73% 
AFTERWARD  

VAL  #  % 
4  6  1.00% 
5  6  1.00% 
6  0  0.00% 
7  6  1.00% 
8  8  1.33% 
9  20  3.33% 
10  18  3.00% 
11  2  0.33% 
12  88  14.67% 
13  32  5.33% 
14  10  1.67% 
15  30  5.00% 
16  38  6.33% 
17  78  13.00% 
18  2  0.33% 
19  52  8.67% 
20  156  26.00% 
S12  0  0.00% 
S13  6  1.00% 
S14  2  0.33% 
S15  0  0.00% 
S16  2  0.33% 
S17  2  0.33% 
S18  6  1.00% 
S19  0  0.00% 
S20  4  0.67% 
21  26  4.33% 
The effect this will have on the next hand dealt is dramatic. The table to the right demonstrates the way that the odds of the second hand compare to the one that was just dealt from a freshly shuffled deck of cards: At the start of the hand, there is a 54.00% likelihood (compared to 33.76%) of receiving a pat hand, and only a 19.33% chance (compared to 32.54%) of receiving a hand that’s likely to bust. Granted, this is true on both sides of the table—but even before the hand is dealt, players are at a distinct advantage because of the four factors listed in the previous section.
Once the cards are dealt, there is a very high likelihood that the majority, if not all, of the cards left to be used as hits will be tenvalue cards. If all of the low cards show, this is an absolute certainty, and players can deviate from basic strategy accordingly. A player should surrender rather than hit his thirteen against the dealer’s seven (because the dealer certainly has 17 and the player is certain to bust) or double down on a twothree if the dealer shows a six (because the dealer is certain to bust).
Again, victory is not guaranteed. If the dealer draws a 20 and all the low cards come out in the player’s hands, it’s certain doom—any hit will bust a stiff hand and nothing will save it. Just as with any other player, the cards must turn in the counter’s favor—but because he has a reliable estimate of the outcome, he can make the best possible choice whatever the situation.
How To Count Cards Odds
As with any other player, a card counter will not walk away with a heap of winnings every time he plays. Because the order of the cards is always random, and because there are equal chances of a good hand being dealt to either side of the table when the count is high, it is by no means a guaranteed winning system—but it does instruct players to wager heavily when their chances of winning are better than usual.