White to move and checkmate in 6.
5r2/1b2P1bk/npqr3p/8/p4p2/1QB2Rn1/6P1/4R1K1 w – – 0 1
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Checkmate in 6
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White to move and checkmate in 6.
5r2/1b2P1bk/npqr3p/8/p4p2/1QB2Rn1/6P1/4R1K1 w – – 0 1
1.exf8=N+ Kh8
(1…Bxf8 2.Qf7+ Bg7 3.Qxg7#)
2.Bxg7+ Kxg7 3.Re7+ Kf6
(3…Kh8 4.Rh7#)
4.Qf7+ Kg5
5.Nh7+
(5.Re5+ Nf5 6.Qxf5+ Kh4 7.Qh5#However this is mate in 7.)
5….. Kg4/Kh4 6.Rxf4#
First I looked at:
1. exf8=Q(?) Bxf8??
2. Qf7+ Bg7
3. Qxg7#
But black’s possibilities to deviate from 1. … Bxf8 are numerous, also including Qc5+ or Ne3+, and for some of those lines I don’t find a mate in 6 though white is clearly better.
So 1. exf8=Q probably isn’t enforcing enough to solve this puzzle.
I try:
1. exf8=N+! Kh8
Only move because of 1. … Bxf8? 2. Qf7+ Bg7 3. Qxg7#.
2. Bxg7+! Kxb7 (only legal move)
3. Re7+! Kh8
The alternatives were:
1. … Kf6 2. Qf7+ Kg5 3. Rf5+ Kg4/Kh4 4. Qxf4#
1. … Kg8? 2. Qf7+ Kh8 3. Qg7#/Qh7#
1. … Kxf8?? 2. Qf7#
And now all enforced seems:
4. Qb2+ Qc3
5. Qxc3+ Rd4
6. Qxc4+ Kg8 (only legal move)
7. Qg7#
But alas, this was mate in 7, needed was 6!
Where did I drop a tempo?
I tried to insert Ng6+ somewhere but couldn’t quite make that work…
Well, my mate in 7 line after 3. … Kh8? was clearly nonsense (though that mate I found was also kind of pretty):
1. exf8N+ Kh8 (1. Bxf8?? 2. Qf7+ mates next)
2. Bxg7+ Kxg7
3. Re7+ Kh8??
4. Rh7#
I missed that mate, and wrote something strange about the alternatives to 3. … Kh8.
It of course goes:
3. … Kf6
Enforced. Only alternative was 3. … Kxf8?? 4. Qf7#.
4. Qf7+ Kg5
Here I looked at the easy to find 5. Re5+(?) Nf5! 6. Qxf5+ Kh4 7. Qxf4# still being 7 moves. But I should not forget the promoted knight!
5. Nh7+! Kg4/Kh4
6. Rxf4#
Nice mate where Pg2, Qf7 and Nh7 and black’s own Ng3 take all the escape fields.
This time I hope it is correct!
An underpromotion problem!
1. efN+ Kh8 (1…B:f8 2. Qf7+ and mate next)
2. B:g7+ K:g7 (forced)
3. Re7+ Kf6 (other moves are met by immediate mates)
4. Qf7+ Kg5 (forced)
5. Nh7+ Kg4/h4
6. R:f4#