The Omega II System of card counting, which was developed by Bryce Carlson and published in his 2001 book Blackjack for Blood, is a level two card counting system. This means that it is more complicated than beginning card counting systems like Knock Out or Hi-Lo. However, when used correctly it is especially strong, with a betting efficiency of up to 99%.

The Omega II system is balanced, meaning that it is based around a count of 0 with a negative count meaning that there are more high cards in the deck and a positive count meaning that there are more low cards. The count is more complicated than the traditional -1, 0, +1 system. Cards are assigned the following values:

• Cards numbered 2, 3 and 7 are assigned a value of 1
• Cards numbered 2, 5 and 6 are assigned a value of 2
• 9s are assigned a value of -1
• 10s, Jacks, Queens and Kings are assigned a value of -2
• 8s and Aces are assigned a value of 0

Though the Omega II system of card counting can be more difficult to learn than simpler card counting systems, it's efficiency makes it well worthwhile. To make the system even more effective you should keep a count of Aces on the side, as Aces are given a value of 0 and do not effect the count. By counting how many Aces have already been dealt vs. how many are still in the deck you can make an even more educated decision about your next play in the game—how much will you bet, will you stand, hit, split or double down?