Playing Chessmaster 9000 on a pretty easy setting, still only managed to draw :)

91.Rc5 would be winning:

crap.. thanks man.. is that technique called building a bridge or something? think i heard about it before. need to study endgame technique more..

FancyKnight, I believe 91. Rc5 Rf8! draws as the white pawn is only on the 4th. The black rook checks the white king ad nauseum on a8/b8, while if the white rook intervenes, the black king steps closer.

The Lucena position can be forced if the pawn were instead on the 5th, then the king himself could stop the rook's checks by stepping onto b7.

The rematch. Had a totally crushing position and then overlooked a nasty stalemate trick!

@Remellion Didn't think about that. And I see if white plays the king to c4 black stops the pawn by threatening to check from the side. Thanks for the lesson!