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Posers and Puzzles

Posers and Puzzles

  1. Subscriber BigDoggProblem
    The Advanced Mind
    17 Sep '06 06:50

    PG in 26.5 moves
    (position after White's 27th move; find the gamescore)
  2. 17 Sep '06 16:45
    Why does black have 3 knights?
  3. Standard member Dragon Fire
    Lord of all beasts
    17 Sep '06 17:39
    Originally posted by laedawg
    Why does black have 3 knights?
    Obviously he has "queened" a pawn.
  4. 17 Sep '06 17:49
    Why on Earth would you choose a Knight over a Queen?
  5. 17 Sep '06 19:33 / 4 edits
    Did you notice White has three rooks?
    In a proof game the moves need only be legal - they do not have to make any sense as moves in an actual game.
    Anyway, what would you play in this position (you are white and it's your turn):

    And a set of little challenges (but don't forget BDP's problem!)
    Find positions with minimal number of chessmen where:
    1. Knight promotion is the only winning move;
    2. Rook promotion is the only winning move;
    3. Bishop promotion is the only winning move;
    4. Knight promotion is the only drawing move (solution above);
    5. Rook promotion is the only drawing move;
    6. Bishop promotion is the only drawing move.
    The best solutions I know of are as follows:
    Challenge no. 1 - 4 pieces;
    Challenge no. 2 - 3 pieces;
    Challenge no. 3 - 5 pieces;
    Challenge no. 4 - 4 pieces;
    Challenge no. 5 - 7 pieces;
    Challenge no. 6 - 6 pieces.
    Can you find the positions?
  6. Standard member Dragon Fire
    Lord of all beasts
    17 Sep '06 20:38
    Originally posted by David113
    Did you notice White has three rooks?
    In a proof game the moves need only be legal - they do not have to make any sense as moves in an actual game.
    Anyway, what would you play in this position (you are white and it's your turn):
    [fen]4K3/r4P2/4k3/8/8/8/8/8[/fen]
    And a set of little challenges (but don't forget BDP's problem!)
    Find positions with min ...[text shortened]... ieces;
    Challenge no. 5 - 7 pieces;
    Challenge no. 6 - 6 pieces.
    Can you find the positions?
    f8=N+
  7. Subscriber BigDoggProblem
    The Advanced Mind
    18 Sep '06 06:24 / 2 edits
    Originally posted by David113

    And a set of little challenges (but don't forget BDP's problem!)

    Can you find the positions?[/b]
    Here's the first three:

    1. Knight promotion is the only winning move;
    wKf5 Bg6 Pg7; bKh6. 1.g8N+!
    2. Rook promotion is the only winning move;
    wKa5 Pc7; bKa7. 1.c8R!
    3. Bishop promotion is the only winning move;
    wKb4 Nd5 Pb7; bKa6 Pa7. 1.b8B!

    The queen was left off the list, because that task isn't possible with 3 units, and trivial with 4 units.
  8. Subscriber BigDoggProblem
    The Advanced Mind
    18 Sep '06 06:26
    Originally posted by laedawg
    Why does black have 3 knights?
    Probably for the same reason White has three Rooks.
  9. Subscriber BigDoggProblem
    The Advanced Mind
    19 Sep '06 21:01
    Originally posted by David113

    And a set of little challenges (but don't forget BDP's problem!)
    Find positions with minimal number of chessmen where:

    4. Knight promotion is the only drawing move (solution above);

    Can you find the positions?
    Seems there are multiple solutions for this one.

    wKh5 Pe7; bKf6 Qg7

    Menaced with ...Qg5#, White's only escape is 1.e8N+, winning the Queen and drawing.
  10. Subscriber BigDoggProblem
    The Advanced Mind
    19 Sep '06 21:21 / 3 edits
    Originally posted by David113

    And a set of little challenges (but don't forget BDP's problem!)
    Find positions with minimal number of chessmen where:

    5. Rook promotion is the only drawing move;

    The best solutions I know of are as follows:
    Challenge no. 5 - 7 pieces;
    I can beat this by 2 units.

    wKc1 Ph7; bKa1 Pa2h2.

    Of course, White can win (1.h8Q#, 1.h8B# ) or lose (1.h8N, 1.K~) but only 1.h8R h1Q+ etc. draws.
  11. Subscriber BigDoggProblem
    The Advanced Mind
    19 Sep '06 21:33
    Originally posted by David113

    And a set of little challenges (but don't forget BDP's problem!)
    Find positions with minimal number of chessmen where:
    6. Bishop promotion is the only drawing move.

    The best solutions I know of are as follows:
    Challenge no. 6 - 6 pieces.
    Using my idea from challenge #5, I can do this one with a mere 4 units.

    wKc2 Pa7; bKa1 Ph2.

    1.a8B is the only drawing move.
  12. 20 Sep '06 16:09
    When I wrote "move X is the only drawing move" I meant that all other moves are losing.
  13. Subscriber BigDoggProblem
    The Advanced Mind
    20 Sep '06 18:20
    Originally posted by David113
    When I wrote "move X is the only drawing move" I meant that all other moves are losing.
    As my examples show, the stip must explicitly state this (or my examples become cooks).
  14. 21 Sep '06 20:23 / 1 edit
    Originally posted by BigDoggProblem
    3. Bishop promotion is the only winning move;
    wKb4 Nd5 Pb7; bKa6 Pa7. 1.b8B!
    Wrong.

    White mates in 103 (!) by 1.b8N.
  15. Subscriber BigDoggProblem
    The Advanced Mind
    22 Sep '06 05:16
    Originally posted by David113
    Wrong.

    White mates in 103 (!) by 1.b8N.
    Prove it.