1.c4! bxc3 2.Ke3 Kg5 3.a4! Kxg4 4.b4! White sacrifices two pawns to create an outside pawn. 4...axb4 5.Kd3! [5.a5? b3 6.Kd3 b2 7.Kc2 Kf4 8.a6 Ke3 9.a7 b1Q+ 10.Kxb1 Kd2 11.a8Q c2+ 12.Ka2 c1Q=+ ] 5...h5 6.a5 h4 7.a6 h3 8.a7 h2 9.a8Q Kg3 10.Qh1 and White will win the h-pawn and the game.
White exploits the position of Blacks imprisoned pieces. 1.Kf7 Nh6+ 2.Kf8 Ng8 3.Ng4! h6 (not 3...Nh6? because after 4.Ne5 Black is mated in two moves) 4.Kf7 Kh7 (White now transfers the Knight to e8 so that the Black King is still imprisoned i.e. the changing of the guard. The King is now free to lose a move by triangulation. Black is then in ZUGSWANG) 5.Ne5(e3) Kh8 6.Nc4! Kh7 7.Nd6 Kh8 8.Ne8 Kh7 9.Ke6! Kh8 10.Kd6! Kh7 11.Kd7 Kh8 12.Ke6 Kh7 13.Kf7 Kh8 14.Nc7 Kh7 15.Ne6 Kh8 16.Nf8 and wins.
Of the five positions this is probably the most difficult. It is a classic superior Knight vs bad Bishop ending with most of Blacks pawns on the same colour as the Bishop.1.d5! This move clears the way for the Knight and the King to penetrate into Blacks position via d4. If White delayed playing this move then Black would play ...d5 with a blocked position. 1...e5 This seems Blacks best defence as his Bishop becomes active. [1...exd5 2.Nd4 Be8 3.f5 gxf5 4.Nxf5+ Kd7 5.Kd4 Bf7 6.Ne3! this move looks the best. (6.Nh6 Bh5 7.Kxd5 Bg6 8.Ng4 Bf7+ and Black seems to hold this position ) 6...Be8 7.Nxd5 Bg6 8.Nf4 Bf5 9.g6 Ke8 10.Kd5 Ke7 11.Kc6 Bd7+ 12.Kc7+- Black cannot hold Whites attack.] 2.fxe5 Bxd5 White has the advantage and will soon obtain a strong passed b-pawn but Black has counter chances on the other wing. 3.exd6+ Kxd6 4.Nd4 Ke5 Black plans to obtain his own passed pawn 5.Nxb5 Kf5 [ 5...Bf7 6.Nd4 Be8 7.Nf3+Kd5 8.Kf4+-] 6.Nd6+ [6.Kd4 Ba8 7.Nd6+ Kxg5 8.b5 Kf4 9.Nxc4 (9.b6 g5 10.b7 Bxb7 11.Nxb7 g4-+) 9...g5 10.Ne5 g4 11.Nxg4 Kxg4 12.Ke5 Kf3 13.c4 Ke314.c5 Kd3 15.c6 Kc4=] 6...Kxg5 7.b5 White will win the Bishop for the b-pawn. 7...Kh4 8.b6 Kh3 9.b7 Bxb7 10.Nxb7 g5 The Knight gets back just in time to stop the g-pawn from queening. 11.Nd6 g4 12.Nxc4 g3 13.Nd2 g2 14.Kf2 Kh2 15.Nf3+ Kh1.White wins.
1.Ra3 Rxa3 2.bxa3 h5 3.a4 h4 4.a5 h3 5.a6 f4 6.a7 f3 7.a8N With this Knight underpromotion White overcomes the stalemate trap which would arise with Q, R or B promotion. 7...Kh2! [ not 7...h2?? 8.Nb6 and White will mate in a few moves.] 8.Kxf2 Kh1 9.Nb6 Kh2 10.Nc4 Kh1 11.Nd6! Kh2 12.Kxf3 Kg1 13.Ne4 h2 14.Ng3 White wins.
