Green non-corner strategy

Remember, you remove a3 and place a marble on a green ring just below or above the first marble. If your opponent jumbs into the red area, you go for the red strategy with isolating two white marbles on a1 and b1. And if he/she jumps into the blue area, you go for the blue strategy with isolating two white marbles on a4 and b5. 

N = marble of free choice

nn = ring of free choice

First marble placed on b2 or b3:

First marble placed on c3 or c4:

First marble placed on d3 or d4:

First marble placed on e3 or e4:

First marble placed on f2 or f3:

First marble placed on g2 or g3: