Point Values
Start with the number 0 (zero.)  Every time any card worth 2 to 6 goes by, mentally add 1 to the count.  Whenever an ace or any card worth 10 goes by, subtract 1.  For 7, 8, or 9, do not change the count.  We define a positive count to favor the player, and a negative count to favor the dealer.  Why?  When tens and aces are in abundance, there is a higher chance for the player to get a Black Jack, and also a much higher chance the dealer will go bust (since dealers must hit on as high as 16.)  Now, when a 10 or ace leave the shoe, there is one less in the shoe, therefore the shoe is slightly less favorable.  That is why we subtract 1 for those cards.  When there are many 2 through 6 cards in the shoe, we will hardly get a Black Jack, and the dealer will most likely finish with a 17 - 21 and not go bust.  Therefore, as these unfavorable cards are removed from the shoe, the shoe has become more favorable to us, so we add to the count.  Each deck has a net count of 0, since there are 4 aces, 16 tens, and 20 cards 2 through 6. Other systems exist, but are harder to learn.  A more accurate system uses these values : 2=+2.5;  3=+3.0; 4=+4.0; 5=+5.0; 6=+3.0; 7=+2.0; 8=0; 9=-1.5; T=-3.5; A=-4.0