Why card counting works

A reader sent me this e-mail:

If the remaining cards are rich in 10s and aces, doesn't the dealer have as much chance to get them as the players? So how does the player have the edge in this situation?

The reader was referring to the playing technique known as card counting where players can track the ratio of small (2 through 6) to big (10, J, Q, K, ace) cards from one round to the next so they would know if the remaining cards to be played are richer in big or small cards. The reader specifically mentions the situation where the remaining cards are rich in 10s and aces. And what he says is true. The dealer has the same chance of getting those 10s and picture cards as the player. However, the playing rules for the player are not the same as for the dealer, and this is what causes the player to have the advantage when the unplayed cards are 10/ace rich. Let me explain.

Let's first look at the dealer and player's chances to get a blackjack. You'll agree that when the unplayed cards are rich in 10s/aces, the chance that the dealer or player will get a blackjack increases. But they both have the same chance of getting the 10 and ace. When the dealer blackjacks (assume the player does not a have a blackjack), the dealer collects the player's losing bet. (Essentially, the house has won even money from the player.) But when the player blackjacks, he doesn't win even money, he wins 3 chips for every 2 wagered. So a dealer blackjack doesn't cancel, if you wish, a player blackjack; the player still has an extra chip. The payoff rules for a blackjack, therefore, favor the player.

Look also at the scenario of doubling down. Obviously, dealers are not permitted to double down, but players can. And when a player doubles down with, say, a 9, 10 or 11, he is hoping to draw a big card to wind up with 19 to 21. His chance of drawing a big card increases when the unplayed cards are richer in 10s/aces. The edge here definitely is in the player's favor.

Let's look at the differences between a dealer getting a stiff hand and the player getting the same (by stiff I mean a hand that could bust with a one-card draw, such as hard 12 through 16). Suppose the dealer has a 16; the rules specify that the dealer must draw, and if the unplayed cards are rich in 10s, his chance of busting increases. The player holding a 16, on the other hand, doesn't have to hit. He could stand when he knows the deck is richer in 10s. In fact, card counters will deviate from the basic playing strategy based on whether the unplayed cards are rich or poor in 10s. The rules for hitting and standing definitely favor the player in a 10-rich deck.

The same can be said for splitting opportunities. An abundance of high cards is usually beneficial to the player, especially when splitting 7s, 8s, 9s and aces. Dealers, of course, can't split. The edge again favors the player in a 10-rich deck.

A bet that is available to the blackjack player, and not the dealer, is the insurance bet. Here a player can bet that the dealer's downcard will give him a blackjack. When the ratio of small and high cards is balanced, the house has the edge on the insurance bet (because they pay less than the true odds on a winning insurance bet). However, when the deck is richer in tens/aces, the dealer has a greater chance of having a blackjack and the insurance bet becomes a profitable bet for the player. The edge here is clearly in the player's favor.

Let's look briefly at who has the edge when the undealt cards are richer in small cards. Certainly, small cards are of no help to a player when he doubles down and in most splits. And for sure you wouldn't want to make the insurance bet if you knew the unplayed cards were rich in small cards. So, small cards don't do a whole lot for players. However, they are very beneficial to the dealer. Why? Because the dealer must always hit his stiff hands, and if the unplayed cards are rich in small cards, he will wind up with a pat 17 though 21, and most likely beat the players. The edge here is definitely in the dealer's favor.

So, I hope you better understand how 10/ace rich decks can favor the player even though the dealer has just as much chance of getting them. Card counters, in fact, will always bet more money when the unplayed cards are rich in 10s/aces for the above reasons. This doesn't mean they always win every hand. Sometimes the dealer or other players will get the 10s/aces from the shoe and the counter will wind up with a stiff hand (been there, done that -- many times). It happens and the counter will take his lumps. But over time, he will win many of those hands in ten/ace rich decks, which will more than cancel the losses and he will end up with a profit. I personally have 30 years of playing experience to back this up.

Knowing when the unplayed cards are 10/ace rich or poor is obviously the goal of card counting. Many average players, unfortunately, shy away from learning card counting because they think it is too difficult to learn. That may have been the case many years ago, but nowadays there are simple card systems that average players can learn in the same amount of time it takes to learn the basic playing strategy. Speed Count is the easiest, in my opinion. Others include K-O, Red Seven, Key Card.

There is really no excuse why average players can't play with the edge when they play blackjack.