The Red Seven card counting system is an unbalanced card counting strategy, similar to the KO Count. You can read more about the Red Seven Count in Blackbelt in Blackjack by Arnold Snyder.
The point values are distributed as per the table below:
2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | A |
+1 | +1 | +1 | +1 | +1 | * | 0 | 0 | -1 | -1 |
*In the Red Seven Count, ONLY red seven's are counted as +1; black seven's are given a value of 0.
The point of an unbalanced card counting system like the Red Seven Count is to eliminate the need to convert the running count into a true count when making betting decisions.