By raising or lowering your bets according to the True Count the house edge can be overcome. By also making variations according to the True Count, the player can stand on a twelve against a two or three when the odds are very high that the hit card will be a ten. This idea is just common sense and should be employed when the decks favor the player and are against the dealer.
Many strategy plays are changed when the count is high or low. Simply think of what some would call rich in high cards and rich in low cards. It is then obvious what a player should do when faced with a hand that can be harmed by hitting or made a great deal better. Basic strategy works well in most instances, but there are playing situations that necessitate a change in strategy. A hand that calls for a DD would be a poor candidate when the deck is rich in low cards. The opposite is true if a low card hit can help the hand
These variation plays will only happen about 10 percent of the time so the changes are not a constant situation. When they do happen, you will DD less.or more, hit break hands more or less and do splits more or less. The moves are based solely on the True Count and not on a feeling or a hunch. If there is not a logical reason for the change the strategy, then do not do it. These variations can also change a DD to a simple hit of the hand or just the opposite. As stated before these are common sense moves and the logic is impeccable.
The study of variation is controlled by the number of times a player is likely to see the situation in the course for normal play. The more likely the face off will happen will determine the priority of the play versus other possible plays. One of the most obvious variations is when to take insurance on a hand. If the deck is high card rich, the odds of a dealer Blackjack are considerably above normal. In this situation, the insurance bet has a high degree of profit build into the bet and the bet has nothing to do with the cards that the player is holding when the dealer shows an Ace.
Statistically this is a very good bet for the player when the True Count is very plus which means the deck is low on cards other than ten count. Rich decks in either direction should always be taken advantage of as the plays have a high probability of winning. This is a truism in more than half the deals as the player starting hand will be between 12-16. As you can see the minus deck would favor this hand often. In single deck the variations happen more frequently and are ample reason to locate single deck games. The percentage player welcomes any extra edge.