Go back
Rook Sacrifice with Horizon Effect

Rook Sacrifice with Horizon Effect

Only Chess

Vote Up
Vote Down

[Event ""]
[Site ""]
[Date "2009.2.1"]
[Round ""]
[White "?"]
[Black "?"]
[TimeControl "-"]
[Result "*"]

1.e4 e6 2.d4 d5 3.Nd2 Nf6 4.e5 Nfd7 5.f4 c5 6.c3 cxd4 7.cxd4 Nc6 8.Ngf3
f6 9.Bd3 fxe5 10.dxe5 Nc5 11.Bb1 Be7 12.a3 a5 13.h4 Qb6 14.Ng5 Kf8
15.Qh5 Bxg5 16.fxg5 Ke7 17.g6 h6 18.Rf1 Rg8 19.Rf7+ Ke8 *
r1b1k1r1/1p3Rp1/1qn1p1Pp/p1npP2Q/7P/P7/1P1N2P1/RBB1K3 w Q - 0 20
BR -- BB -- BK -- BR --
-- BP -- -- -- WR BP --
-- BQ BN -- BP -- WP BP
BP -- BN BP WP -- -- WQ
-- -- -- -- -- -- -- WP
WP -- -- -- -- -- -- --
-- WP -- WN -- -- WP --
WR WB WB -- WK -- -- --
I apologize for the crude diagram.

Modern engines in particular believe that Black is a bit better off here and they typically want to play 20.Qe2?. White however has a clear winning line after 20.Rxg7!, for example:

20.Rxg7 Rxg7 21.Qxh6 Rg8 22.Qh7 Ne7 23.Nf3 Kd7 24.Bg5 Re8 25.g7 Qd8 26.Bg6 Rg8 27.Rc1 b6 28.b4 axb4 29.axb4 Na6 30.Bd3 Nc7 31.Bxe7 Kxe7 32.Rxc7+ Qxc7 33.Qxg8 Qc1+ 34.Kf2 Qf4 35.Qh7 Ra2+ 36.Be2 Qf7 37.g8=Q 1-0

Crafty 20.14 finds the sacrifice in 5 minutes 26 seconds on my laptop.

Chessmaster 9000 SKR takes 18 minutes 22 seconds to find the sacrifice.

Slow Blitz Chess can't find it after a half hour.

1 edit
Vote Up
Vote Down

Hope you don't mind me putting the diagram in properly dana : )

  • 8
  • a
  • 7
  • b
  • 6
  • c
  • 5
  • d
  • 4
  • e
  • 3
  • f
  • 2
  • g
  • 1
  • h
1.e4e6
2.d4d5
3.Nd2Nf6
4.e5Nfd7
5.f4c5
6.c3cxd4
7.cxd4Nc6
8.Ngf3f6
9.Bd3fxe5
10.dxe5Nc5
11.Bb1Be7
12.a3a5
13.h4Qb6
14.Ng5Kf8
15.Qh5Bxg5
16.fxg5Ke7
17.g6h6
18.Rf1Rg8
19.Rf7Ke8

0


      Modern engines in particular believe that Black is a bit better off here and they typically want to play 20.Qe2?. White however has a clear winning line after 20.Rxg7!, for example:

      20.Rxg7 Rxg7 21.Qxh6 Rg8 22.Qh7 Ne7 23.Nf3 Kd7 24.Bg5 Re8 25.g7 Qd8 26.Bg6 Rg8 27.Rc1 b6 28.b4 axb4 29.axb4 Na6 30.Bd3 Nc7 31.Bxe7 Kxe7 32.Rxc7+ Qxc7 33.Qxg8 Qc1+ 34.Kf2 Qf4 35.Qh7 Ra2+ 36.Be2 Qf7 37.g8=Q 1-0

      Crafty 20.14 finds the sacrifice in 5 minutes 26 seconds on my laptop.

      Chessmaster 9000 SKR takes 18 minutes 22 seconds to find the sacrifice.

      Slow Blitz Chess can't find it after a half hour.

      2 edits
      Vote Up
      Vote Down

      • 8
      • a
      • 7
      • b
      • 6
      • c
      • 5
      • d
      • 4
      • e
      • 3
      • f
      • 2
      • g
      • 1
      • h


      Here is the complete game:

      • 8
      • a
      • 7
      • b
      • 6
      • c
      • 5
      • d
      • 4
      • e
      • 3
      • f
      • 2
      • g
      • 1
      • h
      1.e4e6
      2.d4d5
      3.Nd2Nf6
      4.e5Nfd7
      5.f4c5
      6.c3cxd4
      7.cxd4Nc6
      8.Ngf3f6
      9.Bd3fxe5
      10.dxe5Nc5
      11.Bb1Be7
      12.a3a5
      13.h4Qb6
      14.Ng5Kf8
      15.Qh5Bxg5
      16.fxg5Ke7
      17.g6h6
      18.Rf1Rg8
      19.Rf7Ke8
      20.Rxg7Rxg7
      21.Qxh6Rg8
      22.Qh7Ne7
      23.Nf3Kd7
      24.Bg5Re8
      25.g7Qd8
      26.Bg6Rg8
      27.Rc1b6
      28.b4axb4
      29.axb4Na6
      30.Bd3Nc7
      31.Bxe7Kxe7
      32.Rxc7Qxc7
      33.Qxg8Qc1
      34.Kf2Qf4
      35.Qh7Ra2
      36.Be2Qf7
      37.g8=Q

      0



          Edit: (posted 1st to see if everything was correct)

          20.Rxg7 kind of leaps out of you - but could not analyse to that depth.
          Would have gone for it OTB (I know me)
          Then a chance I may have screwed it up (I know me).

          Vote Up
          Vote Down

          What is the Horizon Effect in chess?
          -GIN

          Vote Up
          Vote Down

          Originally posted by Nowakowski
          What is the Horizon Effect in chess?
          -GIN
          http://en.wikipedia.org/wiki/Horizon_effect

          Vote Up
          Vote Down

          Originally posted by Nowakowski
          What is the Horizon Effect in chess?
          -GIN
          When the sun sets over the horizon it gets dark,
          you cannot see the pieces anymore so you go to bed and wait for sunrise.

          Sunset usually happens once a day.

          Vote Up
          Vote Down

          Originally posted by greenpawn34
          When the sun sets over the horizon it gets dark,
          you cannot see the pieces anymore so you go to bed and wait for sunrise.

          Sunset usually happens once a day.
          or you swindle someone into playing in a dark kitchen.
          cheap!

          -GIN

          Vote Up
          Vote Down

          GM Larry Christianson has annotated two nice games in this opening in his "Attack with LarryC" video series with the ICC. Go to chess fm, go to "Attack with LarryC" archives and search "Trashing the Tarrasch"

          Vote Up
          Vote Down

          Originally posted by Nowakowski
          or you swindle someone into playing in a dark kitchen.
          cheap!

          -GIN
          Ah ah - but the computer says it was not a swindle but a damn good move.

          In a nutshell the horizon effect.

          If the computer is only looking 4 ahead and there is a mate in 5
          then it won't see it (obviously - it's horizon is set to 4).

          So you play a move, it plays a move and suddenly it sees it.

          That is when is it starts to to do all these silly moves to stop
          the mate. Giving up it's Queen for check etc. etc.

          I do recall a game years ago when a computer suddenly did this
          and the stong players present and the programmers thought the
          machine had broken down.

          It turns out the computer had seen a mate (missed by all) and
          this was it putting off the mate for as long as possible.

          I'll try and dig out the position - it is most likely quite famous
          in computer circles. The Box was Black, it was a Kingside fianchetto,
          white checks on the back rank and the box blocks the check with
          a Queen. That is all I can recall.

          Vote Up
          Vote Down

          Originally posted by greenpawn34
          Ah ah - but the computer says it was not a swindle but a damn good move.

          In a nutshell the horizon effect.

          If the computer is only looking 4 ahead and there is a mate in 5
          then it won't see it (obviously - it's horizon is set to 4).

          So you play a move, it plays a move and suddenly it sees it.

          That is when is it starts to to do all these si ...[text shortened]... hecks on the back rank and the box blocks the check with
          a Queen. That is all I can recall.
          Duchess vs. Kaissa 1977

          • 8
          • a
          • 7
          • b
          • 6
          • c
          • 5
          • d
          • 4
          • e
          • 3
          • f
          • 2
          • g
          • 1
          • h
          Black to move

          Nobody around understood why Black played 1. ... Re8!? in this position. The answer was that after 1. ... Kg7, 2. Qf8+ mates in a few.

          Vote Up
          Vote Down

          That's it.

          I was close. it sacced a Rook for nothing not a Queen.
          I got the fianchetto bit right though.

          (not to bad considering it 31 years ago.)

          The real scary thing is it does seem just like a few years ago.
          Where did the 80' and 90'd go?

          Cheers

          Vote Up
          Vote Down

          I cked thatfirst position with my engine, and it indeed say Q-e2 after checking 330 milion positions

          Cookies help us deliver our Services. By using our Services or clicking I agree, you agree to our use of cookies. Learn More.