Here is the solution/analysis for this week’s endgame study #5.
Composition by Paul Keres, Magyar Sakkvilág, 1936.
White to Play
1.Nc2+! Ka2
[ 1…Bxc2 2.Qb8
A) 2…b2+ 3.Kxc2 b1Q+ ( 3…h3 4.Qa8# ; 3…Ka2 4.Qa8# ) 4.Qxb1# ;
B) 2…Bd3 3.Qa8+ Ba6 4.Qxa6# ;
C) 2…Ka2 3.Qa7# ;
D) 2…Bb1 3.Qxb3 Ba2 ( 3…c2 4.Qb2# ) 4.Qxc3# ]
[ 1…bxc2 2.Qb8 Ka2 3.Qb4 Ka1 ( 3…Bd3 4.Qa4# ) 4.Qa3# ]
2.Nb4+! Ka1
[ 2…Ka3 3.Nd3 Bxd3 4.Qd6+ Ka4 ( 4…Ka2 5.Qd5 Bb5 6.Qa8+ Ba4 7.Qxa4# ) 5.Qxd3
A) 5…c2 6.Qc4+ Ka3 ( 6…Ka5 7.Qxb3 and White will gobble up the remaining pawns. ) 7.Qb5 b2+ 8.Kxc2 ;
B) 5…Kb4 6.Qd4+ Ka3 7.Qxc3 Ka4 8.Qc5 h3 ( 8…b2+ 9.Kxb2 h3 10.Kc3 h2 11.Qb4# ) 9.Kb2 h2 10.Kc3 h1Q 11.Qb4# ;
C) 5…h3 6.Qc4+
C1) 6…Ka3 7.Qb5 b2+ 8.Kc2 h2 ( 8…b1Q+ 9.Kxb1 h2 10.Kc2 h1Q 11.Qb3# ) 9.Qb3# ;
C2) 6…Ka5 7.Qxc3+ Ka4 8.Qxh3 ;
D) 5…b2+ 6.Kc2 Ka3 ( 6…Kb4 7.Qxc3+ Kb5 8.Kxb2 h3 9.Qxh3 ) 7.Qxc3+ Ka4 ( 7…Ka2 8.Qxb2# ) 8.Qxb2 ]
3.Qa2+ bxa2 4.Nc6 h3
[ 4…Bc2 5.Kxc2 h3 6.Nd4 h2 7.Nb3# ]
5.Nd4 h2
[ 5…Bg8 6.Nc2# ]
6.Nb3#