The EOR is the estimated effect of removing a given card from play, and the resulting impact on the house advantage. The player may gauge the effect of removal for all cards dealt, and assess the current house advantage of a game based on the remaining cards. As larger ratios between point values are used to create a better correlation to actual EOR with the goal of increasing the efficiency of a system, such systems use more different numbers and are broken into classes depending on such as level 1, level 2, level 3, and so on, with regard to the ratio between the highest and lowest assigned point values.