Edward Thorp's Ten Count system is one of the earliest card counting systems known. Like most "ten-count" card counting systems, Thorp's Ten Count tracks the ratio of high cards to low cards in the deck by assigning each card a numeric value, which is then counted as each card is seen.
The values for the Thorp Ten Count can be seen in the table below:
Edward Thorp originally presented his card counting systems in his book Beat the Dealer, which is considered by many to be the beginning of modern card counting. You can read more about Edward Thorp here: