White to move and checkmate in 6. No computer lines please.
3K1k1B/7P/8/7b/2q5/8/p7/1Q6 w – – 0 1
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Friday (Hard) Brain Teaser
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White to move and checkmate in 6. No computer lines please.
3K1k1B/7P/8/7b/2q5/8/p7/1Q6 w – – 0 1
1.Qf5+
A)1…Bf7 2.Ba1 Qd5+ 3.Qxd5 Bxd5 4.h8/Q Kf7 5.Qg7+ Ke6 6.Qf6 mate
B)1…Qf7 2.Ba1 Qxf5 3.h8/Q+ Kf7 4.Qe8 mate !
Option 2 with 2.Bb2:
2. Bb2
Here, black can sacrifice the queen at c7 or c8 to provide either e7 or f7 to his king as a way to escape the mate net for a move or two:
2. …..Qc7
3. Kc7 and
(3….Ke8 4.Ba3 mates in 1; 3….a1(Q) 4.h8(Q) Ke7 5.Qff6#; or 3….Ke7 4.Ba3 Ke8 5.Qb5#) are all mates in 5 overall. Or
2. …..Qc8
3. Kc8 Ke7
4. Qf6 Kf8 (Ke8 5.Qd8#)
5. h8(R)# Other options for black at move 3 are like those in the Qc7 lines immediately above. At move 2, black could check at h4 and cover h8:
2. …..Qh4
3. Bf6 Qf6
4. Qf6 a1(Q) (a1 is only move)
5. h8(Q)# Or
3. …..Qd4
4. Bd4 a1(Q)
5. h8(R)# Or
3. …..Qh7
4. Qh7 and Qg7# on the next move is unstoppable.
Finally,
3. …..Bd5,Bc4, or Bb3
And, now, the shortest mate I can find is
4. Qg6 Qd4 (Qf6 5.Qf6 Bf7)
5. Bd4 with mate on the next move.
3. …..Be8
4. Qe6 Qf6 (Qd4 5.Bd4; Qh7 5.Qe8#)
5. Qf6 Bf7
6. h8(R)#
3. …..Be6
4. Qe6 Qd4 (delays longest)
5. Bd4 a1(Q)
6. h8(Q)#
3. …..Bg8
4. Bh4 Kg7 (Bf7 5. h8(Q)#)
5. h8(Q)Kh8
6. Bf6# and
3. …..Bg6
4. Qc5 Kf7
5. Qe7#
So, 2. …..Qh4 is all mates in 6 or less total.
2. …..Qd3
3. Qd3 Bg8
4. Qf5 Bf7
5. h8(Q)# Or
3. …..Banywhere else
4. h8(Q) mates in 6 moves total or less. Also, a1(Q) loses in 6 moves or less total after h8(Q).
2. …..Qd4
3. Bd4 a1(Q)
4. h8(Q)#
Lastly,
2. …..Qd5
3. Qd5 Bd5
4. h8(Q)Kf7
5. Qe8#
I, also think that 2. Ba1 mates in six or less based on the above analyses, but I am too tired to make sure.
Arrgh! At first I couldn’t figure out how Black could last
for 6 moves, and then when I spotted 3…. Be6 for Black,
I couldn’t figure out how to mate in 6 moves or less. But
I’ve got it now:
1. Qf5+ Bf7 (if 1…. Qf7 2. Qc5+)
2. Ba1 Qh4+
3. Bf6 Be6
4. Qg6 (the double, discovered check Be7+ isn’t quick enough. That’s where my problem lay.)
And now either
4…. Qd4+
5. Bxd4 Bf7 (only move, other than Bg8, where 6. h8=Q is not mate)
6. Qg7#
or
4…. Qxf6+
5. Qxf6+ Bf7
6. h8=Q#
Black can also try 2…. Qc7+ or Qc8+ which are
both met the same way:
2…. Qc7+
3. Kxc7 Ke8
4. h8=Q+ Bg8
5. Qxg8+ Ke7
6. Take your choice of mates here. I’ve counted 14 different
ways: 4 with the Q on g8, 9 with the Q on f5, and 1 by the
bishop. Did I miss any?
I suppose I could also analyse 1…. Qd4+ and 1…. Qd3+
but I’ve spent enough time on this one already.
Lucymarie
The initial queen check seems to cover a lot of squares so lets try that.
Qf5+ Bf7
Bf6 Qd5+
Qxd5 Bxd5
h8=q+ Kf7
Qg7#
Qf5+ Qf7
Qxf7+ Kxf7
Ba1 Kg6
h8=Q etc
1. Qf5+ seems obvious. Black can’t move the K (no legal moves) or interpose the Q (then 2. Qc5+ and 3. Q:e7#)so he must play 1…Bf7. Now 2. Ba1 (as good as any other and better than some) threatens 3. h8Q#, so black must play 2…Qh4+ 3. Bf6 and black is reduced to playing giveaway. 3…Be6 4. Q:e6 Qd4+ 4. B:d4 a1Q and 6. Qe7#
Black has some options along the way, but they all seem to lose quicker. For example 3…Qd4+ 4. B:d4 a1Q 5. h8Q#.
Timoth’ee has solved in a perfect way.Hats off .
But if black’s second move….Qh4+
the game would be different.
The normal game should go as follows.
1)Qf5+ Bf7
2)Bf6,Qd5+
3)Qxd5,Bxd5
4)h8=Q+,Kf7
5)Qg7+,Ke6
6)Qe7+Kf5
7)Qe5+Kg4
The game takes some more moves before white wins.
I have found the best solution to my knowledge in 7 moves.
1)Qf5+,Bf7
2)Ba1,Qh4+
3)Bf6,Bd5
4)Bh4+,Kg7
5)Bf6+,Kf8
6)h8=Q,Kf7
7)Be7#
S.Krishnamurthy