2 hands vs 1...but wait there's more
"For one hand, your optimal bet size is your advantage times your capital divided by variance. For two simultaneous hands, your optimal bet per hand is your advantage times your capital divided by the sum of variance plus covariance. For n simultaneous hands, your optimal bet per hand is your capital divided by the sum of variance plus (n+1) times covariance.
optimal bet per hand = advantage x capital
for n simultaneous hands ___________________________
variance + (n+1) covariance
OPTIMAL BET SIZE-PROPORTION OF YOUR ADVANTAGE TIMES YOUR CAPITAL FOR EACH OF N SIMULTANEOUS HANDS
HANDS PROPORTION
1 .95
2 .70
3 .56
4 .46
5 .40
6 .34
7 .31
Example: your capital is ($100,000) and your advantage is 1%. What is your optimal bet? 1% of ($100,000) is ($1,000). Multiply this times the number in (the) table..Your optimal bets are ($950) for one hand alone, or ($700) one one of each of two hands, or ($560) on each of 3 hands, or ($460) on each of four hands, or ($400) on each of five hands, or ($340) on each of six hands, or ($310) on each of seven hands.
As you can see, the more hands you play, the more optimal betting suggests you should bet. But, playing an extra hand means cutting down on the amount bet on the other hands. Thus, the total bet goes up as number of simultaneous hands goes up, but the total goes up slowly."
Black Jack in Asia
Stanford Wong
I have used this formula with great success.