White to move. How should white proceed?
Source: ChessToday.net
Chess Daily News from Susan Polgar
Kolkata Practical Chess Tacic
About Author
White to move. How should white proceed?
Source: ChessToday.net
In the initial position white is down a rook so taking the knight (either cxd4 or exf4) is probably an even game as white has compensation with the better placement of his pieces and the quality of his knights.
The winning move is
1.Qg4 which threatens mate on g7 but also xrays the unprotected black queen
if 1…Rf7
2.Nxh6+ Kh7/h8
3.Qxe6 picking up the queen
if 1…Qf7 protecting the g7 square and also getting the queen out of the line of fire of the white queen
2.Nxh6+ taking advantage of the pin on the g7 pawn
2…Kh7/h8
3.Qxe6
if 1…g5/g5 then again 2.Nxh6+ capturing the queen on the next move
if 1…Kf7 trying to make a run for it then once again
2.Nxh6+ Ke8 (2…gxh6 3.Qg6#)
3.Qxe6
So in all situations white will be up a queen for a rook since if black tries to pick up the h6 knight at the end of the vaiations then his own knight on d4 is en prise.
1. Qg4 Rf7 (must defend g6; g5 loses to 2. N:h6+ winning the black Q) 2. cd and 3. N:h6+ wins an exchange
1.Qg4
seems to make two threats which cannot both be prevented at once: threatening mate with Qxg7 and a discovered attack on Black’s unprotected queen with Nxh6+.
1…Qf7
gets Black’s queen out of the discovery and protects g7 but fails to 2.Nxh6+ anyway because the only defender of h6 is the pinned g7 pawn and so Black’s queen and king are forked and the queen goes next move.
1…g6
fails quite simply to 2.Qxg6+ Kh8 3.Qg7#
1…g7
fails to 2.Nxh6+ with a discovered attack on the undefended queen.
1…Kf7
gets the Black king out of the pin and protects the Black queen. Unfortunately, as it is the king protecting the queen, it fails to 2.Nxh6+ where Black either moves the king to e8 and loses the queen, or Black takes the white knight with 2…gxh6 and gets checkmated with 3.Qg6# where the queen he came to protect blocks his escape route.
Assuming I haven’t missed anything, this is a beautiful problem because it’s a ‘double attack’ of mate or discovered attack, making it less obvious, but just as effective as a mate or capture double attack because Black is helpless to defend against both threats at once.
1Qg4,Qf7 2Nh6+,Kh7 3Nxf7?
1Qg4,Qf7 2Nh6+,Kh7 3Nxf7?
1Qg4,Qf7 2Nh6+,Kh7 3Nxf7?
1Qg4,Qf7 2Nh6+,Kh7 3Nxf7?
1. Qg4! g5 (alternatives later)
2. Nxh6+ winning the Queen 1-0
1. Qg4! Rf7
2. Nxh6+ winning the Queen 1-0
1. Qg4! Qf7
2. Nxh6+ winning the Queen 1-0
1. Qg4! Kf7
2. Qg6+ Kg8
3. Qxg7+#
1. Qg4! g6
2. Qxg6+ Kh8
3. Qg7+#
1. Qg4!
2. Qxg7+#
Qg4
1. Qg4!!
With double threat Qxg7# or Nxh6+ followed by Qxe6 (there was no Kf7).
Black has no good moves, since Qf7 Nxh6+ followed by Nxf7 doesn’t help.
So black will loose queen for knight here, but in the end white regains knight with cxd5 and then has queen for rook (the rook black is leading with in diagram).
Relatively simple, but the sum of knight geometry, pin and discovered attack made it difficult to see the complete picture.
I for too long tried to make it work to trap bishop after cxd5, but that doesn’t work when black plays accurate.
If I am not mistaken black has just captured at d5.
1.Qg5 threatens mate 1t g7.
1…. Rf7 or Qf7
2.Nxh6+ wins Q in either option.
1. Qg4 threaten mate or win of Black’s queen.