Abstract
The card counting technique known as ‘back-counting’ is treated analytically. The true count at which the back-counter should optimally enter the game is derived, based on maximising his effective yield. That entry count is found to be in the range of +2 to +3 for a typical 6-deck game, depending on the back-counter's risk profile. If he also adopts an ‘exit’ strategy (abandoning play at a table whose true count has dropped below a lower threshold) and optimises the entry and exit counts simultaneously, he can improve his performance slightly further; the optimal exit count is between − 2 and − 3. Because the risk of ruin is very low, he may in addition choose to bet more aggressively than he would if not back-counting—or, conversely, to ‘flat bet’. Criteria are examined for ‘departure’ (abandoning the observation of a table whose true count has yet to reach the entry threshold).