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Previous Next Up Topic Rybka Support & Discussion / Rybka Discussion / Position - Rybka correct, Stockfish wrong? (479 hits)
- - By BrandonSi (***) [us] Date 2010-02-08 16:27 Edited 2010-02-08 16:30
Interesting.. A few engines, including Rybka 3, very quickly isolate

1.Qc2 Bxd5 2.Bxd7 Bc6 

as the correct / appropriate line.

However Stockfish finds it, and disregards it in favor of

1.Qc1 Bxd5 2.Bxd7 Bc6

even after d=21 (I did not go further).

I'm assuming Rybka is correct? Is this a problem with Stockfish evaluations?

2r1rk2/pp1nppb1/2bp2p1/3N2Bp/2PqP3/1P5B/P2QRPPP/5RK1 w - - 0 1


Analysis by Stockfish 1.6.2 JA:

1.Qb4 b6 2.Qa3 a5 3.Rfe1 b5
  +/-  (1.29)   Depth: 6   00:00:00  19kN
1.Qb4 b6 2.Qa3 a5 3.Rfe1 b5 4.Rd2
  +/-  (1.21)   Depth: 7   00:00:00  25kN
1.Qf4 Be5 2.Qh4 e6 3.Ne7 Nf6 4.Nxc8 Rxc8
  +-  (1.53)   Depth: 7   00:00:00  34kN
1.Qf4 Qe5 2.Qh4 a6 3.Bf4 Bf6 4.Qg3 Qd4 5.Bh6+ Kg8
  +-  (1.57)   Depth: 8   00:00:00  95kN
1.Qf4 Qe5 2.Qh4 b5 3.cxb5 Bxb5 4.Bf4 Bf6
  +/-  (1.25 --)   Depth: 9   00:00:00  143kN
1.Qc2 e6 2.Be3
  +-  (1.89 !)   Depth: 9   00:00:00  195kN
1.Qc2 Bxd5 2.Bxd7 Bc6 3.Bxe8 Rxe8 4.Rd1 Qe5 5.f4 Qc5+ 6.Rf2 Rc8
  +-  (1.69)   Depth: 10   00:00:01  287kN
1.Qc2 Bxd5 2.Bxd7 Bc6 3.Bxe8 Kxe8 4.Rd1 Qe5 5.Bc1 Kf8 6.f3 b5 7.Be3 bxc4 8.Qxc4
  +-  (1.73)   Depth: 11   00:00:01  436kN
1.Qc1 Bxd5 2.Bxd7 Bc6 3.Bxe8 Kxe8 4.Rd1 Qe5 5.f3 b6 6.Qe3 Kf8
  +-  (1.93)   Depth: 11   00:00:01  816kN
1.Qc1 Bxd5 2.Bxd7 Bc6 3.Bxe8 Kxe8 4.Rd1 Qe5 5.Qe3 Rd8 6.f3 Kf8 7.f4
  +-  (2.10)   Depth: 12   00:00:01  994kN
1.Qc1 Bxd5 2.Bxd7 Bc6 3.Bxe8 Kxe8 4.Rd1 Qe5 5.Qe3 Rd8 6.f3 Qc5 7.Qxc5 dxc5 8.Rxd8+ Kxd8 9.e5 Bd7 10.Kf2
  +-  (2.18)   Depth: 13   00:00:02  1878kN
1.Qc1 Bxd5 2.Bxd7 Bc6 3.Bxe8 Kxe8 4.Rd1 Qc3 5.f3 Qxc1 6.Bxc1 f6 7.Be3 b6 8.Kf2 Kf7 9.Ree1 g5
  +-  (2.02)   Depth: 14   00:00:03  3013kN
1.Qc1 Bxd5 2.Bxd7 Bc6 3.Bxe8 Kxe8 4.Rd1 Qc3 5.Rc2 Qe5 6.f3 b6 7.Bf4 Qc5+ 8.Be3 Qa5 9.Bd4 Bxd4+ 10.Rxd4 Kf8 11.Rd1 Qc5+ 12.Rf2
  +-  (2.06)   Depth: 15   00:00:05  4613kN
1.Qc1 Bxd5 2.Bxd7 Bc6 3.Bxe8 Kxe8 4.Bf4 Kf8 5.Rd1 Qc5 6.Be3 Qa5 7.Bh6 b6 8.Qe3 Bxh6 9.Qxh6+ Kg8 10.f3 Qe5 11.Qe3
  +-  (2.10)   Depth: 16   00:00:08  8165kN
1.Qc1 Bxd5 2.Bxd7 Be6 3.Rd1 Qc3 4.Qxc3 Bxc3 5.Bh6+ Kg8 6.Bxe8 Rxe8 7.Be3 b6 8.Bd4 Bb4 9.Be3 Rc8 10.Bd2 Ba3 11.Bc3 Bc5
  +-  (2.06)   Depth: 17   00:00:14  17181kN
1.Qc1 Bxd5 2.Bxd7 Be6 3.Rd1 Qe5 4.Bxc8 Rxc8 5.Bh6 Qa5 6.Bxg7+ Kxg7 7.Qe3 f6 8.f3 b5
  +-  (2.10)   Depth: 18   00:00:30  37304kN
1.Qc1 Bxd5 2.Bxd7 Bc6 3.Bxe8 Kxe8 4.Bf4 Qc3 5.e5 Qxc1 6.Rxc1 dxe5 7.Bxe5 f6 8.Bc3 Rd8 9.Rd2 Rxd2 10.Bxd2 e5 11.Rd1 Bf8 12.Be3 b6 13.f3
  +-  (2.10)   Depth: 19   00:00:54  65512kN

Analysis by Rybka 3 32-bit:

1.Qc2 Bxd5 2.Bxd7 Bc6
  +/-  (1.06)   Depth: 6   00:00:00  6kN
1.Qc2 Bxd5 2.Bxd7 Bc6 3.Bxe8 Kxe8 4.Rd1
  +/-  (1.05)   Depth: 7   00:00:00  10kN
1.Qc2 Bxd5 2.Bxd7 Bc6 3.Bxe8 Rxe8 4.Qd2 Qxd2 5.Bxd2 b5 6.Rc1
  +/-  (1.13)   Depth: 8   00:00:00  27kN
1.Qc2 Bxd5 2.Bxd7 Bc6 3.Bxe8 Rxe8 4.Qd2 Qxd2 5.Bxd2 b5 6.Rc1 bxc4 7.Ree1 Bb5 8.bxc4
  +/-  (1.21)   Depth: 9   00:00:01  46kN
1.Qc2 Bxd5 2.Bxd7 Bc6 3.Bxe8 Kxe8 4.Bf4 Kf8 5.Rd1 Qc5 6.Be3 Qa5 7.f3
  +/-  (1.28)   Depth: 10   00:00:02  97kN
1.Qc2 Bxd5 2.Bxd7 Bc6 3.Bxe8 Kxe8 4.Bf4 Kf8 5.Rd1 Qc5 6.Be3 Qa5 7.f3
  +/-  (1.28)   Depth: 11   00:00:02  133kN
1.Qc2 Bxd5 2.Bxd7 Bc6 3.Bxe8 Rxe8 4.Rfe1 b6 5.Bc1 Qc5 6.Bb2 Rc8 7.Bxg7+ Kxg7 8.Qc3+ f6 9.Rd1
  +/-  (1.33)   Depth: 12   00:00:09  450kN
1.Qc2 Bxd5 2.Bxd7 Bc6 3.Bxe8 Rxe8 4.Rfe1 b6 5.Bc1 Qc5 6.Bb2 Rc8 7.Bxg7+ Kxg7 8.Qc3+ f6 9.Rd1 Bb7
  +/-  (1.36)   Depth: 13   00:00:12  622kN
Parent - - By yanquis1972 (****) [us] Date 2010-02-08 17:03
i'm partial to Qc1 myself. i don't know that there is a correct answer; surely one move is obejctively better but to me it looks like with proper play white wins either way. i think Qc1 maintains the overwhelming pressure on black's position better than Qc2.
Parent - - By BrandonSi (***) [us] Date 2010-02-08 17:31
Yes, I agree. Perhaps I should not have used the word "correct" and "wrong." :)

It's interesting that Stockfish seems the only engine I tried to end up choosing Qc1.
Parent - - By Nelson Hernandez (Bronze) [us] Date 2010-02-08 19:25
Interesting, your studying a position that appears only in a 1997 WMCCC game.  Qc2 was played, as you no doubt know.
Parent - By BrandonSi (***) [us] Date 2010-02-08 19:35
Yes, Qc2 was played. I'm not studying the position. I'm studying the engines that are studying the position. :)
Parent - By Knight (**) Date 2010-02-09 05:53
Naum 4.1 and Thinker 5.4C seem to favor Qc1 too
Note that mp versions may have different choices sometimes
Previous Next Up Topic Rybka Support & Discussion / Rybka Discussion / Position - Rybka correct, Stockfish wrong? (479 hits)

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