>>388-389
The players are here.

Black( x1 , y1 , z1 )
Red( x2 , y2 , z2 )
Brown( x3 , y3 , z3 )
Green( x4 , y4 , z4 )

The barycenter is given by this formula.

Barycenter( x5 , y5 , z5)
x5 = ( x1 , x2 , x3 ) / 3
y5 = ( y1 , y2 , y3 ) / 3
z5 = ( z1 , z2 , z3 ) / 3

Then you can get a vector which the Green Player should to go.
The vector is Barycenter to current Green Player position.