The conventional definition may be useful for players determine how much it'll price them to play, given the knowledge they already know. In Caribbean stud poker, for example, the home edge is 5.22%, which is near that of double zero roulette at 5.26%. However the ratio of average cash lost to common money wagered in Caribbean stud is only 2.56%. The player only looking at the house edge may be indifferent between roulette and Caribbean stud poker, based mostly only the home edge. A card counting system assigns a degree rating to each card rank (e.g., 1 level for 2–6, zero points for 7–9, and −1 level for 10–A). When a card is exposed, a counter adds the rating of that card to a operating total, the 'rely'.