First, you have to know basic strategy (BS), which is the best possible way to play each time for each possible circumstance when you are not counting cards. In other words, you have to play how an odds-calculating non-counting robot would play each hand. There are diagrams online that show you how to play with basic strategy. If I remember correctly, if you play perfect BS for millions of hands, you end up winning 43% of the time.* In the high-low version of card-counting, you assign a -1 value to aces, faces, and tens, a 0 value to 7-9, and +1 to 2-6. You combine these totals when you see them on the table. You keep that running count in your head, and watch the remaining cards in the shoe (that 6 to 8 deck box of cards). You divide the running count by the number of approximate actual decks remaining in the shoe, and you get the true count, which you also have to remember. If the true count goes negative, you bet low or leave the table. If it goes positive, you bet more per hand. Also you make variations of your basic strategy play based on what the true count is. That's where you tilt the odds slightly in your favor. *see first comment

Ace counts as 1.The numbers from 2 to 10 count as their values.Jack counts as 11,queen as 12,king as 13. You have to be less than equal to 21 and beat the other opponent in count.If you get exact 21,it's a black jack.If both your numbers are equal it's a push,i.e. no one wins and no one looses.