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Posers and Puzzles

Posers and Puzzles

  1. 14 Jun '05 19:44
  2. 14 Jun '05 20:26
    d8N ?
  3. 14 Jun '05 22:40
    This is interesting. It is clear that White must avoid stalemate/perpetual check, sacrificing pieces, and mating with the capture of the Black queen
    1...a1Q whether with check or no is inevitable.
    I am pretty sure the second move is 2.Ba2 but I just have to get some sleep now. "Morning is wiser, than evening," as the saying goes. I will know more tomorrow.
  4. Standard member XanthosNZ
    Cancerous Bus Crash
    15 Jun '05 03:17
    1. d8=N a1=Q+ 2. Ba2 Qxa2+ 3. Qa5 Qxa5+ (3. ... Qd5+ 4. Rb7 Qxa5+ 5. Kb8 Qa8+ 6. Kxa8 Kxe8 7. Rge7+ Kxd8 8. Rb8# 1-0) 4. Ra7 Qd5+ 5. Rgb7 Qxd8+ 6. Bxd8 Kxe8 7. Nf6+ Kxd8 8. h8=Q# 1-0

    Can anyone find any faults with that?
    Smileys better not mess up my notation.

  5. 21 Jun '05 08:51 / 1 edit
    Originally posted by XanthosNZ
    1. d8=N a1=Q+ 2. Ba2 Qxa2+ 3. Qa5 Qxa5+ (3. ... Qd5+ 4. Rb7 Qxa5+ 5. Kb8 Qa8+ 6. Kxa8 Kxe8 7. Rge7+ Kxd8 8. Rb8# 1-0) 4. Ra7 Qd5+ 5. Rgb7 Qxd8+ 6. Bxd8 Kxe8 7. Nf6+ Kxd8 8. h8=Q# 1-0

    Can anyone find any faults with that?
    Smileys better not mess up my notation.

    Good one.

    A bishop would give mate in 9.

    If you ask a computer to solve the situation (not necessarily mate in 8), with infinite thinking time, it takes quite a while for it to come up with... a bishop. (Well, Fritz2 does anyway.) Somehow it prefers the bishop over the knight.
    I thought that was kind of funny. Felt like I cheated the computer with this one. A little revenge for all those years of losing.
  6. 21 Jun '05 09:23
    Originally posted by Shiny Knight
    Good one.

    A bishop would give mate in 9.

    If you ask a computer to solve the situation (not necessarily mate in 8), with infinite thinking time, it takes quite a while for it to come up with... a bishop. (Well, Fritz2 does anyway.) Somehow it prefers the bishop over the knight.
    I thought that was kind of funny. Felt like I cheated the computer with this one. A little revenge for all those years of losing.
    I know I gave only the first move, but you guys also didn't show WHY d8=N leads to 8 and d8=B leads to 9 moves, especially since in the variation you show the piece on d8 is captured before it has moved. So, look for a variation where black does not capture on d8 on the fith move....
  7. 21 Jun '05 09:38 / 1 edit
    Originally posted by Mephisto2
    I know I gave only the first move, but you guys also didn't show WHY d8=N leads to 8 and d8=B leads to 9 moves, especially since in the variation you show the piece on d8 is captured before it has moved. So, look for a variation where black does not capture on d8 on the fith move....
    The knight covers b7.

    When the black Queen goes 4...d5+, the knight, instead of the rook on g7, jumps inbetween. Then it takes one move less to mate.

    But maybe I'm going wrong somewhere.
  8. 21 Jun '05 09:45
    Originally posted by Shiny Knight
    The knight covers b7.

    When the black Queen goes 4...d5+, the knight, instead of the rook on g7, jumps inbetween. Then it takes one move less to mate.

    But maybe I'm going wrong somewhere.
    No, that is not the difference. 4. ... Qd5+ 5.Nb7 only results in mate-in-9 after 5. ... Qc6.

    The difference comes after 5.Rgb7.
  9. 21 Jun '05 09:53 / 1 edit
    Originally posted by Mephisto2
    No, that is not the difference. 4. ... Qd5+ 5.Nb7 only results in mate-in-9 after 5. ... Qc6.

    The difference comes after 5.Rgb7.
    You're right!

    I found another way of explaining it, I think...

    If there's a bishop, then on the 5th move for black the queen can postpone white's mate by not taking the piece on d8 but just go to h1 for example.

  10. 21 Jun '05 10:27
    Originally posted by Shiny Knight
    You're right!

    I found another way of explaining it, I think...

    If there's a bishop, then on the 5th move for black the queen can postpone white's mate by not taking the piece on d8 but just go to h1 for example.

    You have given a part of the explanation. There are several variations where black can live longer than 8 with a bishop, and not with the knight on d8:

    All after 5.Rgb7:

    - Qc5 6.Ne6+
    - Qh1 6.Bfe7+ the knight on d8 prevents the king escape to f7
    - Kxe8 6.h8Q Qf7 fails on Nxf7
    - Qc6 6.Nxc6
    - Qe6 6.Nxe6
    - Qc4 6.Be7+ Kxe8 Nf6# (the knight on d8 covers f7)
  11. 21 Jun '05 10:35
    Originally posted by Mephisto2
    You have given a part of the explanation. There are several variations where black can live longer than 8 with a bishop, and not with the knight on d8:

    All after 5.Rgb7:

    - Qc5 6.Ne6+
    - Qh1 6.Bfe7+ the knight on d8 prevents the king escape to f7
    - Kxe8 6.h8Q Qf7 fails on Nxf7
    - Qc6 6.Nxc6
    - Qe6 6.Nxe6
    - Qc4 6.Be7+ Kxe8 Nf6# (the knight on d8 covers f7)
    Wow, thanks for that!
    I never took the effort.
    I only knew it was right because my computer finally, after three weeks, said so, 12 years ago.