The Red 7 Count

Updated 24 August 2026

Red 7 is unbalanced like KO, and adds one wrinkle: red sevens count +1 and black sevens count zero. We computed its betting correlation at 0.977 — against 0.963 for Hi-Lo — from the effect each card has on the game, rather than copying the figure from a book.

How it compares, and how we know

Splitting the sevens by color is a trick to get an unbalanced system closer to a balanced one's accuracy without adding a level. It sounds fiddly and stops being so within an hour of practice.

The number that ranks counting systems is betting correlation: how closely the system’s tags track the actual effect each card has on your edge. We computed it rather than copying it — by removing one card of each rank from the shoe, recalculating the entire game, and correlating the result with the tags. The full method is here.

Is it worth switching from Hi-Lo?

Probably not. The gain over Hi-Lo is 0.014 of correlation, which translates into a small fraction of a percent of edge. A single miscount per hour costs more than that.

Who it actually suits: People who want KO's simplicity with slightly better numbers, and who do not mind noticing card colors.

This is the part the system comparisons usually skip. The difference between counting systems is small. The difference between counting accurately and counting sloppily is not.

Every system, with the numbers

Computed for six decks, dealer stands on soft 17, using the effect of removal for each card rank.

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By Martin Kosek · every number on this site is computed by us, not copied.