Páginas

quinta-feira, 23 de novembro de 2017

Xadrez - Mate em 2! (Robert Clyde Moore)

Robert Clyde Moore, The Problemist, 2003.
Código FEN: 5N2/2pQP2p/2PP1ppP/1P1kqbR1/1PN5/1P1P1K2/5B2/4R2B w - - 0 1.

As Brancas jogam e dão xeque-mate em 2 lances!

(White to play and give checkmate in 2 moves!)

PCFilho

9 comentários:

  1. Respostas
    1. Hint: the Black King, Queen and Bishop are in the same line as the White Rook.

      This means that if the Queen moves, the Bishop will become pinned; and if the Bishop moves, the Queen will become pinned.

      Excluir
    2. (In other words, Queen and Bishop are half-pinned.)

      Excluir
    3. There is an astonishing number of "half-pins" in this problem!

      Excluir
    4. That is exactly the goal of the author: he claims that this problem holds the world record of most half-pins in a chess problem. :)

      Excluir
    5. How many half-pins are there in this problem?

      Excluir
    6. According to the author, the solution explores 15 half-pins.

      Excluir
    7. According to this source ( https://www.chessproblem.net/viewtopic.php?f=44&t=672 ):

      "For over 80 years the world record for half-pins was 11. The man who finally broke the record, Robert Clyde Moore, worked on-and-off on the task for 30 years before he was successful. The new record of 15 half-pins was formerly thought to be impossible."

      Excluir
  2. "Two units are said to be half-pinned [against the King] when one of them becomes completely pinned when the other moves." - this is how John Rice defines a half-pin in his "Chess Wizardry: The New ABC of Chess Problems".

    In other words: when two chess pieces are half-pinned against the King, and one of them moves, the other becomes fully pinned – this is the "half-pin" theme in chess problems.

    This problem currently holds the world record of half-pins, with 15 in total, all involving the Black Queen and Bishop.

    1. Bc5!!
    1. ... cxd6 2. Nb6#
    1. ... fxg5 2. Rxe5#
    1. ... Qxe7 2. dxe7# (1st half-pin: the Queen moved, and the Bishop became fully pinned, unable to stop checkmate by capturing the Queen)
    1. ... Qxd6 2. Ke3# (2nd half-pin: the Queen moved, and the Bishop became fully pinned, unable to stop checkmate by interposing in the Bishop's attack)
    1. ... Qe3+ 2. Kxe3# (3rd half-pin: the Queen moved, and the Bishop became fully pinned, unable to stop checkmate by interposing in the Bishop's attack)
    1. ... Qe6/Qh2 2. Q(x)e6# (4th half-pin: the Queen moved, and the Bishop became fully pinned, unable to stop checkmate by capturing the Queen)
    1. ... Qd4/Qc3/Qb2/Qa1/Qxe1 2. dxc7# (5th half-pin: the Queen moved, and the Bishop became fully pinned, unable to stop checkmate by capturing the Queen)
    1. ... Qe4+ 2. dxe4# (6th half-pin: the Queen moved, and the Bishop became fully pinned, unable to stop checkmate by capturing the Pawn)
    1. ... Qe2+ 2. Kxe2# (7th half-pin: the Queen moved, and the Bishop became fully pinned, unable to stop checkmate by interposing in the Bishop's attack)
    1. ... Qf4+ 2. Kxf4# (8th half-pin: the Queen moved, and the Bishop became fully pinned, unable to stop checkmate by interposing in the Bishop's attack)
    1. ... Qg3+ 2. Kxg3# (9th half-pin: the Queen moved, and the Bishop became fully pinned, unable to stop checkmate by interposing in the Bishop's attack)
    1. ... Bxd7 2. Kf2# (10th half-pin: the Bishop moved, and the Queen became fully pinned, unable to stop checkmate by interposing in the Bishop's attack)
    1. ... Be6 2. Qxe6# (11th half-pin: the Bishop moved, and the Queen became fully pinned, unable to stop checkmate by capturing the Queen)
    1. ... Bg4+ 2. Kxg4# (12th half-pin: the Bishop moved, and the Queen became fully pinned, unable to stop checkmate by interposing in the Bishop's attack)
    1. ... Bh3 2. Ne3# (13th half-pin: the Bishop moved, and the Queen became fully pinned, unable to stop checkmate by capturing the Knight)
    1. ... Be4+ 2. dxe4# (14th half-pin: the Bishop moved, and the Queen became fully pinned, unable to stop checkmate by capturing the Pawn)
    1. ... Bxd3 2. dxc7# (15th half-pin: the Bishop moved, and the Queen became fully pinned, unable to stop checkmate by interposing in the Queen's attack)

    ResponderExcluir

Regras para postar comentários:

I. Os comentários devem se ater ao assunto do post, preferencialmente. Pense duas vezes antes de publicar um comentário fora do contexto.

II. Os comentários devem ser relevantes, isto é, devem acrescentar informação útil ao post ou ao debate em questão.

III. Os comentários devem ser sempre respeitosos. É terminantemente proibido debochar, ofender, insultar e/ou caluniar quaisquer pessoas e instituições.

IV. Os nomes dos clubes devem ser escritos sempre da maneira correta. Não serão tolerados apelidos pejorativos para as instituições, sejam quais forem.

V. Não é permitido pedir ou publicar números de telefone/Whatsapp, e-mails, redes sociais, etc.

VI. Respeitem a nossa bela Língua Portuguesa, e evitem escrever em CAIXA ALTA.

Os comentários que não respeitem as regras acima poderão ser excluídos ou não, a critério dos moderadores do blog.