This is my formula
The count I chose I call Unbalanced Zen Halves. System tags are {-1,1,2,2,3,2,1,0,-1,-2}.
An observation I made on the 6:5 game is that the EOR of the ace is almost exactly half that of a ten, as is that of the nine. So a Zen count is not a compromise, it's perfect. Any Zen count will probably work well but I added the Halves tags for the five and nine because to beat 6:5 you'll need all the help you can get.
This sim was done with the Atlantic City rules: H17, DOA, nDAS, RO6
Playing Indices:
12 vs. 2 : 2
12 vs. 3 : 1
12 vs. 4 : -1
12 vs. 5 : -3
12 vs. 6 : -5
13 vs. 2 : -3
13 vs. 3 : -3
15 vs. X : 1
16 vs. 9 : 3
16 vs. X : -2
16 vs. A : 1
DD 9 vs. 2 : -1
DD 9 vs. 7 : 3
DD 8 vs. 5 : 2
DD 8 vs. 6 : 1
DD A8 vs. 5 : 0
DD A8 vs. 6 : -3
Split XX vs. 5 : 4
Split XX vs. 6 : 3
Insurance at 0
Spread (in units):
Spread = 3(RC-1)
RC <= +1 : 1
RC= +2 : 3
RC= +3 : 6
RC= +4 : 9
RC= +5 : 12
RC= +6 : 15
RC= +7 : 18
RC>= +8 : 20
Results: very dependent on the number of hands in the game.
Playing One Hand ($10 BU):
Hands IBA Win Rate/100 SD/hand Desirability Index
1 0.997% $25.92 5.65 4.59
2 1.351% $36.79 5.87 6.27
3 1.232% $31.65 5.61 5.64
4 0.554% $11.53 4.69 2.46
Playing Two Hands
Hands IBA Win Rate/100 SD/hand Desirability Index
2 1.372% $37.61 4.96 7.58
3 1.135% $29.03 4.72 6.14