Rook and Pawn versus Bishop and Pawn(s)

Black should never have lost this endgame because his opponent had little hope of creating either a zugzwang or a passed pawn. When the seven-man ending arose at move 78 he played correctly for a long time but gradually the situation became critical.

In the diagram position, at move 113, time was probably very short, explaining the subsequent blunders. White threatens Kxe5 but Black can safely play either ...e4 or ...f4. He was trying to exchange the last White pawn so preferred ...f4, but after doing so he went wrong several times and eventually managed to lose the ending of King and bishop against king and rook which normally should be a draw.

M. Voigt - D. Margraf
86th German Championship, Saarbrücken 2015

1.e4 c5 2.Nf3 d6 3.Bb5+ Nc6 4.0-0 Bg4 5.h3 Bh5 6.c3 a6 7.Ba4 b5 8.Bc2 Nf6 9.d3 e5 10.Nbd2 Be7 11.Re1 0-0 12.Nf1 d5 13.Ng3 Bg6 14.Nh4 d4 15.Nhf5 dxc3 16.bxc3 b4 17.Ba4 Rc8 18.Bg5 bxc3 19.Bxc6 Rxc6 20.Rc1 h6 21.Qa4 Rc8 22.Qxa6 Ra8 23.Nxe7+ Qxe7 24.Bxf6 gxf6 25.Qc4 Qe6 26.Rxc3 Qxc4 27.Rxc4 Rxa2 28.Rxc5 Rd8 29.Ne2 Rd2 30.Nc1 h5 31.g4 Kg7 32.Kg2 Rb8 33.Re3 Rbb2 34.Rf3 h4 35.Rc6 Rd1 36.Rc3 Re1 37.Nb3 Rbb1 38.Re3 Rxe3 39.fxe3 Rb2+ 40.Kf1 Rh2 41.Nc1 Rxh3 42.Ne2 Rh1+ 43.Kf2 Rd1 44.Ng1 Rd2+ 45.Kf1 Rd1+ 46.Kf2 Rd2+ 47.Kf3 Kh6 48.Nh3 Rd1 49.Nf2 Rg1 50.Ke2 Rb1 51.Rc2 Kg5 52.Kf3 Rf1 53.Rd2 Ra1 54.Nh3+ Kh6 55.Kf2 Ra3 56.Rd1 Ra2+ 57.Kf3 Ra3 58.Nf2 Kg5 59.Rc1 Ra6 60.Rc8 Kh6 61.Rh8+ Bh7 62.Rd8 Ra3 63.Rd6 Kg7 64.Rc6 Bg6 65.Rc2 Rb3 66.Ra2 Rc3 67.Kg2 Rxd3 68.Nxd3 Bxe4+ 69.Kh3 Bxd3 70.Kxh4 Bc4 71.Rc2 Be6 72.Kh5 Bb3 73.Rd2 Be6 74.Rd6 Bb3 75.Rb6 Bd1 76.Kh4 Bf3 77.g5 fxg5+ 78.Kxg5
78...Be4 79.Ra6 Bd3 80.Ra7 Be4 81.Re7 Bg6 82.Ra7 Be4 83.Ra6 Bd3 84.Rd6 Be4 85.Rd7 Bc6 86.Re7 Be4 87.Rc7 Bg6 88.Rc6 Be4 89.Rc1 Bg6 90.Rg1 Be4 91.Rf1 Bd3 92.Rf2 Be4 93.Rb2 Bd3 94.Kg4 Kg6 95.Rb6+ f6 96.Rb8 Be2+ 97.Kg3 Kf5 98.Kf2 Bd3 99.Ke1 Ba6 100.Kd2 Bf1 101.Rf8 Bg2 102.Kd3 Bf1+ 103.Kc3 Bg2 104.Rh8 Bf3 105.Rh4 Bg4 106.Kc4 Bd1 107.Kd5 Bf3+ 108.Kd6 Be2 109.Ke7 Kg5 110.Rh2 Bg4 111.Rh8 f5 112.Rg8+ Kh4 113.Kf6
113...f4 [113...e4 should hold comfortably but Black is fixated on eliminating the last White pawn.] 114.Kxe5 fxe3?! Understandable and not losing but creating counterplay by 114...f3 should draw quite simply: 115.Rf8 (115.Rh8+ Bh5 116.Rf8 Kg3 and the advanced passed pawn ensures a draw.; 115.Kf4 f2 116.Rxg4+ Kh5 (Not 116...Kh3?? 117.Rg3+ and Rf3 wins.) 117.Kg3 f1Q 118.Rh4+ Kg5 119.Rg4+ ) 115...Kg3 White's king is misplaced for dealing with the f-pawn so it will be a draw.] 115.Kf4 Bh5 [115...Be2 also holds; Black does not need the pawn if he is careful. 116.Rg1 Kh3 or Kh5; there is no forced mate.] 116.Rg1 Kh3 117.Kxe3 Be8 Kh2 or those B moves that do not blunder the piece still hold. 118.Kf4 Ba4?? The fatal mistake. Common sense should have told Black to post the bishop on the long diagonal: 118...Bc6 119.Rg3+ Kh2 ; 118...Kh2 is also sufficient.] 119.Rg3+! Kh4 Now White combines threats to the bishop with mating threats. There is no defence. [119...Kh2 lasts a bit longer 120.Kf3 Bb3 121.Kf2 and Black will eventually be mated.] 120.Ra3 Bd1 121.Ra1 Bc2 122.Ra2 1-0