P.s:
Last nights results was encouraging for the part trying to win; both H3 and SF4 won with the black pieces from the 2. diagram. I will test more and try to understand.
I think there is a (deep) zugzwang issue. I dont get it yet, but as soon as black get a pawn to g4, then it seem like white must either give up the control of the 1. or 2. rank, and in either case black is able to force it through. Because if the white pawn must move from f2 to f3, then its spells disaster ( the fort is not longer there).
A kind of positon that repeats itself is one like this:
I believe this is won for black because of the pawn on g4 . Since white dont want to trade rooks, one scenario is that the B get pined on f2. Then if the black king can come to c1, its an all trade on f2 and ...Kd2 will win the game.
I also remember a theme with black having doubled rook on the 2. rank. White king on h1 felt the need to play Bg1 to cover h2. Suddenly the black Rd2 moved to d7 and threatened ...Rh7+. It forced a rook swap and the win was fairly easy after that.
Im not sure, but it seems like its a deep winning method in these kind of positoins. I will keep on with my research.
Ben