Ok I use ko which is weak for 1d but still it gets about double the hourly rate of ko for 6d at 1/2 the spread. Also, I guess I have to say that I have only played about 45 hours of single deck total. However, I've lost 350 units playing it. When I last played at El Cortez, it just seemed like I couldn't win. Then I play 6d with a much higher house edge and I win at it. This is probably just negative variance, but does ko have a really high standard deviation for single deck or what?