domingo, 18 de maio de 2014

Xadrez - Mate em 2! (Harry Potter)

Cena do filme Harry Potter e a Pedra Filosofal.
Código FEN: 5r1k/1pN1R1pp/1Pb5/n3P1n1/7N/b1Q5/7P/1R4K1 b - - 0 2.

Um problema cinematográfico: as Pretas jogam e dão xeque-mate em 2 lances!

(A cinematic problem: Black to play and give checkmate in 2 moves!)

Esta posição aparece no filme Harry Potter e a Pedra Filosofal, tendo sido idealizada pelo mestre internacional Jeremy Silman. Os três personagens principais são peças do jogo: Harry Potter é o Bispo em a3, Ron é o Cavalo em g5, e Hermione é a Torre em f8.

(This position appears in the movie Harry Potter and the Sorcerer's Stone, having been devised by International Master Jeremy Silman. The three main characters are pieces in the game: Harry Potter is the Bishop on a3, Ron is the Knight on g5, and Hermione is the Rook on f8.)

No filme, o movimento-chave não foi o escolhido, por um motivo importante (qual?). Em vez disso, os heróis optaram por um mate em 3 lances. Você consegue encontrar a solução deles?

(In the movie, the key move was not chosen, for an important reason (which one?). Instead, the heroes chose a mate in 3 moves. Can you find their solution?)

PCFilho

8 comentários:

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  3. Here's the mate in 2:
    1 ... Bc5+ 2 Qxc5 Nh3#

    And here's the mate in 3, I think (I don't remember what happened in the movie to that detail):
    1 ... Nh3+ 2 Qxh3 Bc5+ 3 Qe3 Bxe3#

    Incidentally, the chess game scene is the only scene from that movie that I actually liked, because the White queen was bashing the crap out of piece after piece.

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  4. And the reason why the key move was not played because it would have required Harry to sacrifice himself.

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  5. Well done, Jake!!

    1. ... Bc5+!! is the key move for the position:
    1. ... Bc5+!!
    2. Qxc5 Nh3#

    However, the Bishop on a3 was exactly Harry Potter, and well, Harry Potter couldn't sacrifice himself.

    So, in the movie, the Knight on g5 (who was Ron) stepped in to sacrifice himself and save the day:
    1. ... Nh3+!
    2. Qxh3 Bc5+
    3. Qe3 Bxe3#

    International Master Jeremy Silman tells the full story behind this famous chess scene here.

    :)

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    Respostas
    1. As Jeremy Silman's site unfortunately does not exist anymore, I copy his text here:

      Creating the Harry Potter Chess Position
      by Jeremy Silman

      When I was asked to create the chess position for Harry Potter And The Sorcerer’s Stone, I was more than delighted. Throughout my life, I’ve watched movies and TV shows make a joke of real chess positions and real chess lingo. Now, after years of seething, I finally had a chance to do the job right.

      My gripes were the following:

      * When referring to an opening system, the actors would never say, "Ah, that’s my favorite line in the Sicilian Defense.” Instead they would blurt out, "Hey Jeb! You are playing the Farmer Smith line against the Oak Tree Defense.” I’ve never understood why they couldn’t use a real opening name in the script.

      * When referring to a famous player, they would never say, "Oh, there goes Alekhine!” Instead, we would always get some bastardized Russian name: "Oh, there’s goes Ragmazagolsky!”

      * The actors were never taught how to move the pieces correctly. A real chess player doesn’t push the piece meekly forward, he grabs the sucker and smashes it down on a square. If he captures, one hand moves his piece and simultaneously cranes the enemy unit off the board, almost faster than the eye can follow.

      * In about 20% of the scenes I’ve watched, the chessboard has actually been incorrectly placed, with a dark square in White’s right hand corner (it’s supposed to be a light square in that corner).

      * Invariably, no matter how strong the players are supposed to be, one will think for quite a long time, smile, confidently make his move, and his opponent will move something and say, "Checkmate!” (Does any strong player EVER say checkmate?).

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    2. Clearly, I was faced with stemming this tide of insanity. Unfortunately, many of these ideas faded when I read the first Potter book and was faced with the problem at hand: What position would I create that would justify Ron sacrificing himself?

      After spending many hours – day after day for a few weeks – on the phone to the screenwriter in Los Angeles and the producer in England (who insisted that the first move should be a capture), I finally decided on the following dynamic situation:
      (FEN: 5r1k/1pN1R1pp/1Pb5/n1r1P1n1/7N/b2p4/7P/1R1Q2K1 w - - 0 1)

      Harry is the Bishop on a3, Ron is the Knight on g5, and Hermione is the Rook on f8. Black has lost his Queen, but he has a strong attack against the White King. Black’s immediate threat is 1…Nh3 mate, so White begins with…

      1.Qxd3

      This eats a pawn (thereby making the producer happy!) and prevents the Knight’s intrusion into h3. She also threatens to capture Harry on a3! Note that I had the Queen make the capture because I wanted to do everything possible to turn this piece into something the young fans hated. In other words, I wanted to turn the White Queen into the scene’s villain.

      1...Rc3!

      A nice little combination, since the sacrifice of the Rook adds to the Queen-hatred by the audience. The real point, of course, is that it frees the c5-square for the Harry-Bishop.

      2.Qxc3

      The Queen captures the Rook and once again threatens to end Harry’s life! It looks bad for our heroes, but is this really true? Note that I created a logic problem here. Black can force a mate in two moves, but that would NOT be the correct solution. Can you figure out why?

      2…Nh3+!

      A faster mate is possible by 2…Bc5+ 3.Qxc5 Nh3 mate. Unfortunately, this calls for the sacrifice of HARRY, something that would end the quest immediately and is therefore completely unacceptable.

      By sacrificing himself, Ron pulls the Queen away from its control over the c5-square.

      3.Qxh3

      This is the only legal move.

      3…Bc5+

      Suddenly White’s King has no move, and the Queen is forced to step in the way in a vain effort to safe its Monarch.

      4.Qe3 Bxe3 mate.

      I designed this to be an important moment. To me, the audience would get an enormous amount of emotional satisfaction with Harry’s conquest of the hateful Queen.

      Here’s the whole sequence from start to finish:
      (video)

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    3. Unfortunately, movie dynamics once again turned a well thought out chess situation into mumbo-jumbo (though it looked very energetic on the big screen). The length of the film demanded some cuts, so the moves of this whole scene were more or less slashed to …Nh3+ (Ron’s sacrifice) and …Be3 mate (notice that …Be3 doesn’t capture the Queen… very, very sad. I still feel that this was a real missed opportunity and would have enriched the whole on-screen scene immeasurably.).

      After the movie I found myself deluged with questions like:

      "Why can’t anyone tell what the position is?” (Evidently, the people who designed the pieces didn’t consider this to be important.).

      "Why isn’t your name in the credits?” (Sigh… I was hoping nobody would notice that. If you watch the credits role, you will see everyone from the hairdressers to the donut delivery boy given thanks for their part in the creation of the film. The omission of the "chess guy” shows just how far down the food chain we are!).

      "Didn’t grandmaster Speelman design the chess scenes for Potter?” (No! He was the chess guy for The Luzhin Defense.).

      "Was this position taken from a master game?”

      This final question has spawned some funny controversy on the web. In fact, in issue 35 (Summer, 2002) of Kingpin magazine, International Master Gary Lane says that the game Jovanovic - Manzardo, Imperia 1967 was the inspiration for the Potter position:

      1.e4 d5 2.exd5 Nf6 3.c4 c6 4.dxc6 Nxc6 5.Nf3 e5 6.d3 e4 7.Qe2 Bb4+ 8.Bd2 0–0 9.dxe4 Nxe4 10.Qd3 Qe7 11.Be2 Re8 12.a3 Nxd2 13.Nbxd2 Bf5 14.Qe3 Qf6 15.Qb3 Bxd2+ 16.Kf1 Nd4 17.Nxd4 Qxd4 18.Rd1 Rxe2 19.Kxe2 Re8+ 20.Kf1 Bd3+ 21.Kg1 Re2 22.Rf1 Qxf2+ 23.Rxf2 Re1+ 24.Rf1 Be3 mate.

      Sorry guys, but I had never heard of this ridiculous game until Lane published it in Kingpin. Another myth goes down the drain!

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