30 ( +1 | -1 ) You could have wonI played this position against Fritz 8 and it beat me. It's not enough for white to just shuffle the king or rooks back and forth. Black can exploit a pin down the g file to threaten the f5 pawn and the rook on h1. White ends up having too many pins to thwart and something will give in the end.
44 ( +1 | -1 ) i agree with johnrowellI haven't had a very close look at the position, but I think that black can manage to win this.
Black should pay Rg8, then move the B to c3. The white king can now not stay at g2, because black can play Rh5 and threaten to take on f5 (the g pawn is pinned). The rook cannot help because the bishop could always chase it off from d2.
So the king must go west through f1. This opens up a likely attack with the queen and bishop.
49 ( +1 | -1 ) Not only......Does have Black have the potential to break through in the manner johnrowell has demonstrated (trebling the heavy pieces on the h-file, and exploiting the pin on White's g-pawn), but don't overlook the potential residing in Black's protected and passed e-pawn (and the powerfully placed extra bishop is not to be sneezed at, neither). Even if you can't find a clear way to win, as Black you can afford to poke and prod to see what shakes. White has absolutely no play: all he can do is defend (react to Black's initiative). You ain't gonna lose! Cheers, Ion