Cecil's Saturday Puzzle - September 27, 2008 from the Winnipeg Free Press
White to move and mate in 3 (Jacobs)
But 1. Qd7 axb1(N) 2. Nxc2+ Ka2 3. Qxd5# works !
and the other lines work with the Q going to f5 or h7 instead of g6.
A most unusual position.
I immediately saw a mate in 5 with
1.Qd1 axb1(Q) 2.Nc2+ Ka2 3.Nb4+ Ka1 4.Qa4+
1. Nc2+ Kxb1 2. Na3+ Ka1 obviously doesn't work.
I immediately saw a mate in 5 with
1.Qd1 axb1(Q) 2.Nc2+ Ka2 3.Nb4+ Ka1 4.Qa4+
1. Nc2+ Kxb1 2. Na3+ Ka1 obviously doesn't work.
I tried a line (which I forgot now except that the Q was mating on e4 except for the pawn on d5.
So, let's try something nonintuitive (like some of the other problems we have looked at). With the idea of Q having access to the h7-b2 diagonal.
1. Qe8
one line ...axb1(Q) 2. Nb3+ Ka2 3.Qa4#
1.Qe8 Kxc1 2. Qb3+ Ka1 3. Nb3#
so the bishop must move 1. Qe8 Bc3 2. Nb3+ Kxb1 3. Qg6#
So, let's try something nonintuitive (like some of the other problems we have looked at). With the idea of Q having access to the h7-b2 diagonal.
1. Qe8
one line ...axb1(Q) 2. Nb3+ Ka2 3.Qa4#
1.Qe8 Kxc1 2. Qb3+ Ka1 3. Nb3#
so the bishop must move 1. Qe8 Bc3 2. Nb3+ Kxb1 3. Qg6#
Is that it ?
Two questions to answer. What is the difference between Qe8 and Qd7 ?
Both give access to the same diagonal even after e6. And what if Black plays the bishop to b4 and block a mate by Ba3. Because otherwise the bishop is rather useless as all the mating lines involve white squares. But that doesn't appear to be a factor.
Two questions to answer. What is the difference between Qe8 and Qd7 ?
Both give access to the same diagonal even after e6. And what if Black plays the bishop to b4 and block a mate by Ba3. Because otherwise the bishop is rather useless as all the mating lines involve white squares. But that doesn't appear to be a factor.
Speaking of blocking...what if instead of axb1(Q), Black tries axb1(N) to block on a3 - I think that ruins all my efforts.
But 1. Qd7 axb1(N) 2. Nxc2+ Ka2 3. Qxd5# works !
and the other lines work with the Q going to f5 or h7 instead of g6.