basicly this was the stategy:
Blackjeck => you can stop at any time but the dealer has to go to 17 before he can quit.
So if the dealer has 16 he has to take an other card. Now if you know that the previous hand a lot of small cards were taken out of the game you know the chance is greater that the dealer would get a high card so you stop early because of that and let the dealer go bust.
Theire strategy:
2-6= +1
7-9=0
A-K-Q-J-10= -1
Now you ony have to remember 1 number and add or subtract from it. You start with 0. if the number gets positive the chances are greater that the dealer would hit a hight card and go bust.
Example
You see the following cards pass: Q-5-K-4-9 == -1+1-1+1+0 = 0 now if you play long enough you have a statitical number that when positive the odds of the dealer going bust are higher an negative the odds of the dealer staying under 21 is greater.
Finally the casino kicked every player out they suspected of card counting. (they identified em with the geekisch looks and the concentration it takes to follow the cards and calculate the number (you can't start talking to your neighbor or you'll lose track))
