Practice Your Card Counting

About Card Counting (as described in Wikipedia)
Card counting is a card game strategy used to determine when a player has a probability advantage. The term is used almost exclusively to refer to the tracking of the ratio of high cards to low cards in blackjack, although it is sometimes used to refer to obtaining a count of the distribution or remaining high cards in trick-taking games, such as contract bridge or spades. This article deals only with card counting as it applies to blackjack.

Count Strategy2345678910JQKA
Hi-Lo11111000-1-1-1-1-1
Ten Count11111111-2-2-2-21
Wizard Ace/Five000100000000-1
KO11111100-1-1-1-1-1
Hi-Opt I01111000-1-1-1-10
Hi-Opt II11221100-2-2-2-20
Zen Count11222100-2-2-2-2-1
Omega II1122210-1-2-2-2-20
Revere's Point Count12222100-2-2-2-2-2
Revere's Adv Plus Minus1111100-1-1-1-1-10

Card counting in blackjack
The principle behind counting cards in blackjack is that a deck of cards with a higher proportion of high cards (tens and aces) to low cards is good for the player, while the reverse is true for the dealer. A deck rich in tens and aces improves the player's odds because blackjacks (which offer a higher payout than other winning hands) become more common, the dealer is more likely to bust a stiff hand, and double-downs are more successful.[1]

Card counters raise their bets when the ratio of high cards to low cards in the deck is skewed in their favor. Some card counters also watch a game and only enter when the count becomes favorable. This tactic is called back-counting or "wonging". Card counters also make strategy adjustments based on the ratio of high cards to low cards. These two adjustments to their betting and playing strategy can give players a mathematical advantage over the house.

Contrary to the popular myth, card counters do not need savant qualities in order to count cards, because they are not tracking and memorizing specific cards. Instead, card counters assign a heuristic point score to each card they see and then track only the total score. (This score is called the "count".)[2] This myth was portrayed in the movie Rain Man, where the savant character Raymond Babbit counts through six decks with ease and a casino employee comments that it is "impossible" to count six decks.

The plus-minus count
Basic card counting assigns a positive, negative, or null value to each card (2 through ace). As each card is dealt, the running count is adjusted by each card's assigned value. There are multiple card-counting systems in use, but a plus-minus count—such as the Hi-Lo system proposed by Harvey Dubner in 1963[3] and later refined by Julian Braun and Stanford Wong[4]—is one of the more basic and illustrative systems.

In the Hi-Lo system, the cards 2 through 6 are assigned a value of +1. Tens (and face cards) through aces are assigned a value of -1. Cards 7, 8, and 9 have a value of zero (so they can be ignored).

The Hi-Lo system is an example of a balanced card-counting system, in that there are an equal number of +1 and -1 cards in the deck, so a count of all 52 cards would result in an end count of 0.[5]