White to move. How should white proceed?
Source: ChessToday.net
Daily Chess Improvement: Find the best continuation!
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White to move. How should white proceed?
Source: ChessToday.net
1. Rd7 Bxd7
2. Qd8+ Be8
3. Qxe8+ Rg8
4. Qxg8#
3. Qe8 Bf8
4. Qxf8 Rg8
5. Qxg8#
Some different variation just for fun.
1.Rd7 Be7
2.Rxe7 Bf7
3.Rxf7 Qa8(to stall 4.Rf8#)
4.Qxg7#
Here are some positions to test your chess engines on. Best thing to do is let the engine play against itself to see if it can find mate.
White to mate in 15
8/8/8/2p5/1pp5/brpp4/1pprp2P/qnkbK3 w – – 0 1
White to mate in 24
B2n4/7p/4p2p/4P1np/k1KP3p/8/1P2p3/4Bb2 w – – 0 1
The mate in 24 line should start with 1.Bh1, right? I can immediately see that black must respond with 1. …h3 since the other lines are going to lead to mate of the immobilized black king within about 5 moves by my count as the other black moves eventually frees the light squared bishop to deliver the mate- or allows white to play the combo of Bb4 followed by b3#. So, then white will alternate the bishop from h1 to a8 as black slowly marches the pawn line on the h-file to repeated deaths on h1 until those pawn moves are used up (it was exactly this motif- a common one in long mate puzzles- that clued me immediately to Bh1/Ba8).
Do the engines really have a problem with this puzzle?
Stockfish 6 64 solved with ease. Most engines today shouldn’t have a problem but there are engines out there that will not be able to solve this problem without a data base like Syzygy.
Yancey’s plan is perfectly o.k. However certain points
(1) Black has to withhold moving N at d8 when white B is at h1 as it immediately leads to mate.
When white B is at a8 and …. Nb7 mate is delayed by 1 move.
(2) when white B is at a8 or h1 and if black plays ….. Bg2 it must be captured else …. Bd5+ is a nuisance.if it comes after white has captured the N played to f3 or e4 black B can be ignored and white can plan Bb4 followed by b3#.
when 17th move is complete white B is at h1 and black last free P is at h2.Now 18.Ba8 is an opportunity for black to play 18…. Nb7. So a possible set of moves.
1.Bh1 h3 2.Ba8 h2 3.Bh1 h4 4.Ba8 h3 5.Bh1 h5 6.Ba8 h1=Q 7.Bxh1 h2 8.Ba8 h1=Q 9.Bxh1 h4 10.Ba8 h3 11.Bh1 h2 12.Ba8 h1=Q 13.Bxh1 h6 14.Ba8 h5 15.Bh1 h4 16.Ba8 h3 17.Bh1 h2 18.Ba8 Nb7 19.Bxb7 h1=Q 20.Bxh1 Bg2 21.Bxg2 Nf3 22.Bb4 Nd2+ 23.Bxd2 e1=Q 24.Bc6#
After 21…. Nf3 I feared stalemate but managed to carry it through.
As for the mate in 15, I have no insight right now. I can see what the first move must be, but after that, I don’t immediately see how to proceed.
There are 2 main keys in the position that mates in 14. The pawn has to move one square on the first move and it has to promote to only one minor piece. I’ve actually found mate in 11 on this one…
I think maybe I see the potential line in the mate in 15- an underpromotion to a knight, capture of the pawns on c4 and/or c5, and mate via Nxb3 when black is forced to replay the queen to a1. I need to work out, then, whether or not white has to play h3 or h4 on the first move- it surely matters given the underpromotion to a knight.
The first move should be h3 in the mate in 15 puzzle. If white plays h4, the knight will never be able to attack b3 without the queen coming to a2 on the next half move.
I have not gone through all the moves but white should capture c5 and then c4 with the N and then Na5 followed by Nxb3#.capturing c4 only will give black a choice of play between c4 and Qa1 which will not evoke zwugzwang.
Chess engines think only forward but humans backwards also (that is the sad part of it!)
a skeleton variation to support my view is as follows
1.h3 Qa2
2.h4 Qa1
3.h5 Qa2
4.h6 Qa1
5.h7 Qa2
6.h8=N Qa1
7.Ng6 Qa2
8.Nf4
(8.Ne5 Qa1 9.Nxc4 Qa2 10.Na5 c4 11.Nxc4 Qa1 12.Na5 Qa2 is a draw)
8…Qa1
9.Ne6 Qa2
10.Nxc5 Qa1
11.Na4 Qa2
12.Nb6 Qa1
13.Nxc4 Qa2
14.Na5 Qa1
15.Nxb3#
But mate in 11 moves is difficult for me to imagine.
Mate in 11 goes like this:
1. h3 Qa2 2. h4 Qa1 3. h5 Qa2 4. h6 Qa1 5. h7 Qa2 6. h8=N Qa1 7. Ng6 Qa2 8. Ne5 Qa1 9. Nxc4 Qa2 10. Na5 Qa1 11. Nxb3#
My bag, mate doesn’t happen in 11. I had an oversight…
Whether to move 1.h3 or 1.h4 can be decided very quickly. After even number of moves black Q will be at a1. Similarly “h” P if it moves one square at a time and the N also will move on alternate squares will be at a black square after even number of moves. a5 being a black square right move is 1.h3. actual number needs calculation.