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Up Topic The Rybka Lounge / Test Positions / Gaw Paw Sicilian
- - By Bonuskent (*) Date 2010-07-20 20:48 Edited 2010-07-20 20:51
Hi there!

Now I’ll give you a position as I’ve tested on hundreds of engines the last 15 years. The position is difficult (at least it was difficult some years ago), tactical and has a clear solution.

1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 Qb6 (I think Rolf Martens called this the Gaw Paw variation. He also invented the Snake Benoni as well as many other slightly obscure variations.) 6.Be3 (The main line is 6.e5) 6…Ng4? (“With equal chances”, Martens wrote some 20 years ago. Black gets a hard life after 6…Qxb2 7.Ndb5, but after Lars Karlssons 6...a6! black has a normal Sicilian game.)

rnb1kb1r/pp1p1ppp/1q2p3/8/3NP1n1/2N1B3/PPP2PPP/R2QKB1R w KQkq - 0 7


This is the position and the main line of the solution is 7.Qxg4 Qxb2 8.Kd2 Qxa1 9.Nxe6 fxe6 10.Bb5. The first time I looked at the variation I was assisted by the strongest program at that time, some version of Genius back in the 90s. I simply had to try this burn out and while pondering on move number nine I wanted to do something good with the f1-bishop, but what? As a last try before taking the pieces back I smashed the pawn on e6 and then suddenly Genius became very happy! At that time computer analyzing was like searching the world with magnifying glass. You really had to come close to see what was there.

Since that I’ve been speculating about what happens in the search. One of my guesses was that those early engines wanted big sacrifices to be followed up with checks, otherwise the sacs were unlikely to be correct and the search was terminated. It didn’t surprise me that later programs easily found 9.Nxe6. I was more impressed that they also started to find 8.Kd2. Today the fastest engine plays 7.Qxg4 in less than a second and even plays 6…a6 because it finds the refutation of 6…Ng4.

Through this short sequence of moves different engines shows huge difference in speed. I wonder what makes Rybka so fast? Do you have an easy explanation, Vas? After all a move like Ke1-d2 normally don’t work early in the Sicilian. Normally a good engine shouldn’t waste time on it, but what, from the engines point of view, makes it different this time?
Parent - - By Dadi Jonsson (Silver) [is] Date 2010-07-20 22:41
I remember reading about the Gaw Paw variation. I tested this position with 8 recent engines running in single-core mode with 256MB hash. After about 20 minutes all engines had settled on 7.Qxg4 and followed the main variation you gave up to Black's 9th move. HIARCS was the last engine to switch to 7.Qxg4, while both Rybka and Naum found it after 6-7 seconds.
[hl=pgn]DeepShredder12UCIx64  [+2.19]  d=20  7.Qxg4 Qxb2 8.Kd2 Qxa1 9.Nxe6 Qxc3 10.Kxc3 dxe6 11.Bc4 Nc6 12.Rd1 g6 13.Kd2 Bg7 14.Bc5 b6 15.Ba3 a6 16.Ke3 Bd7 17.Bf1 (0:18:05) 561373kN
DeepJunior11.2.x64  [+2.09]  d=19  7.Qxg4 Qxb2 8.Kd2 Qxa1 9.Nxe6 Qxc3 10.Kxc3 dxe6 11.Kb2 Nc6 12.Qg3 g6 13.c3 Bg7 (0:16:04) 1554900kN
Naum 4.1 x64  [+1.86]  d=21  7.Qxg4 Qxb2 8.Kd2 Qxa1 9.Nxe6 Qxc3 10.Kxc3 dxe6 11.Qg3 a6 12.Be2 Nc6 13.Rd1 g6 14.Kb3 e5 15.Kb2 Bg7 16.Bc5 Bf8 17.Bxf8 (0:09:54) 555391kN
stockfish-18-64-ja  [+2.94]  d=28  7.Qxg4 Qxb2 8.Kd2 Qxa1 9.Nxe6 Qxc3 10.Kxc3 dxe6 11.Kb2 Bd7 12.Qg3 Nc6 13.Bb5 a6 14.Be2 Ne7 15.h4 h5 16.c3 Rc8 17.Bd3 g6 18.Bd4 Rg8 19.Qf4 Bg7 20.Bxg7 Rxg7 21.Bc2 (0:18:03) 1096743kN
komodo-12-64-ja  [+1.92]  d=24  7.Qxg4 Qxb2 8.Kd2 Qxa1 9.Nxe6 Qxc3 10.Kxc3 dxe6 11.Be2 Bd7 12.Rd1 Bc6 13.Qf4 Nd7 14.Bd4 Rg8 15.Kb2 Be7 16.Bf3 Rc8 17.e5 a6 18.Bxc6 Rxc6 19.Qe3 f6 20.f4 Kf7 21.Qh3 Rh8 22.Kb1 h6 23.Qb3 b5 24.exf6 Nxf6 25.Qd3 (0:19:28) 1320481kN
DeepSjeng30_x64  [+2.00]  d=19  7.Qxg4 Qxb2 8.Kd2 Qxa1 9.Nxe6 Qxc3 10.Kxc3 dxe6 11.Qg3 Bd7 12.Kb2 Bc6 13.Be2 Nd7 14.Rd1 Be7 15.Bd4 Rg8 16.Qf4 a6 17.f3 Rc8 (0:24:10) 1173860kN
Rybka 4 x64  [+1.58]  d=21  7.Qxg4 Qxb2 8.Kd2 Qxa1 9.Nxe6 Qxc3 10.Kxc3 dxe6 11.Kb2 Bd7 12.Bc4 Nc6 13.Rd1 Ne5 14.Qe2 Be7 15.Bb5 Bc6 16.f4 a6 17.Bxc6 Nxc6 18.Bb6 Rc8 19.Qe3 h6 20.Kb1 (0:23:37) 110177kN
Hiarcs13.1MP  [+0.82]  d=21  7.Qxg4 (0:21:53) 454123kN
Parent - - By dragon49 (****) [us] Date 2010-07-21 00:31
On my Quad I7-920 running at stock speed:

New game
rnb1kb1r/pp1p1ppp/1q2p3/8/3NP1n1/2N1B3/PPP2PPP/R2QKB1R w KQkq - 0 1


Analysis by Deep Rybka 4 SSE42 x64:

1.Bc1 Nc6 2.Ncb5 Nxd4 3.Nxd4 Nf6 4.Qd3 e5 5.Nf5 Qb4+ 6.c3 Qxe4+ 7.Be3
  =  (-0.12)   Depth: 6   00:00:00  7kN
1.Rb1 Nxe3 2.fxe3 Nc6 3.Bb5 e5 4.Nf5 a6 5.Bxc6 dxc6
  =  (-0.09)   Depth: 6   00:00:00  10kN
1.Rb1 Nxe3 2.fxe3 Nc6 3.Be2 Bc5 4.Na4 Qa5+ 5.c3 Bxd4 6.exd4 b5 7.Nc5 0-0
  =  (-0.11)   Depth: 7   00:00:00  12kN
1.Rb1 Nxe3 2.fxe3 Nc6 3.Be2 Be7 4.0-0 0-0 5.Qd2 Ne5 6.Na4 Qb4
  =  (-0.03)   Depth: 8   00:00:00  18kN
1.Bc1 Nc6 2.Qxg4 Nxd4 3.Bd3 h5 4.Qg5 h4 5.h3 Qc5 6.0-0 Qxg5 7.Bxg5 a6 8.Bf4 Be7
  =  (0.09 !)   Depth: 9   00:00:00  54kN
1.Bc1 Nf6 2.e5 Bc5 3.Be3 Ng4 4.Na4 Qa5+ 5.c3 Bxd4 6.Bxd4 Nxe5 7.b4 Qd5
  =  (0.21)   Depth: 9   00:00:00  77kN
1.Bc1 Nf6 2.Nb3 Bb4 3.Bd3 d5 4.exd5 Nxd5 5.Bd2 Nxc3 6.bxc3
  +/=  (0.26)   Depth: 10   00:00:00  151kN
1.Bc1 Nf6 2.Nb3 Bb4 3.Bd3 d5 4.exd5 Nxd5 5.Bd2 Nxc3 6.bxc3
  +/=  (0.26)   Depth: 11   00:00:00  211kN
1.Qxg4 Qxb2 2.Kd2
  +/=  (0.38 !)   Depth: 12   00:00:01  487kN
1.Qxg4 Qxb2 2.Kd2 Bb4 3.Ndb5[] Qxa1 4.Qxg7
  +/=  (0.53 !)   Depth: 12   00:00:01  505kN
1.Qxg4 Qxb2 2.Kd2 Bb4 3.Ndb5[] Qxa1 4.Qxg7
  +/-  (0.93 !)   Depth: 12   00:00:01  534kN
1.Qxg4 Qxb2 2.Kd2 Qxa1 3.Nxe6 Qxc3+ 4.Kxc3[] dxe6 5.Kb2 Nc6 6.Bb5 Bd7 7.Rd1 a6 8.Be2 b5 9.Bb6 Rb8 10.Bc7 Rc8 11.Bd6 Bxd6 12.Rxd6 g6 13.Qg5 h6 14.Qf6 Rg8
  +-  (1.68)   Depth: 12   00:00:03  1204kN
1.Qxg4 Qxb2 2.Kd2[] Qxa1 3.Nxe6 Qxc3+ 4.Kxc3[] dxe6 5.Kb2 Nc6 6.Bb5 Bd7 7.Rd1 a6 8.Be2 b5 9.Bb6 Rb8 10.Bc7 Rc8 11.Bd6 Bxd6 12.Rxd6 g6 13.Qg5 h6 14.Qf6 Rg8
  +-  (1.68)   Depth: 13   00:00:04  1327kN
1.Qxg4 Qxb2 2.Kd2[] Qxa1 3.Nxe6[] Qxc3+ 4.Kxc3[] dxe6 5.Kb2 Bd7 6.Be2 Nc6 7.Rd1 0-0-0 8.Qg3 e5 9.Bb5 f6 10.f3 Be6 11.Rxd8+ Kxd8 12.Bxc6 bxc6 13.Bxa7 Ke8
  +-  (1.56)   Depth: 14   00:00:05  1673kN
1.Qxg4 Qxb2[] 2.Kd2[] Qxa1 3.Nxe6[] Qxc3+ 4.Kxc3[] dxe6 5.Kb2 Bd7 6.Be2 Nc6 7.Rd1 0-0-0 8.Qg3 g6 9.c3 Bg7 10.f4 h5 11.e5 h4 12.Qf3 Kb8 13.Bc5
  +-  (1.52)   Depth: 15   00:00:07  2568kN
1.Qxg4 Qxb2[] 2.Kd2[] Qxa1 3.Nxe6[] Qxc3+ 4.Kxc3[] dxe6 5.Kb2 Bd7 6.Qg3 Bc6 7.Be2 Nd7
  +-  (1.54)   Depth: 16   00:00:13  4697kN
1.Qxg4 Qxb2[] 2.Kd2[] Qxa1 3.Nxe6[] Qxc3+ 4.Kxc3[] dxe6 5.Kb2 Bd7 6.Qg3 Bc6 7.Be2 Nd7 8.Rd1 h5 9.Bd4 Rc8 10.Bd3 b6 11.f3 h4
  +-  (1.53)   Depth: 17   00:00:18  6718kN
1.Qxg4 Qxb2[] 2.Kd2[] Qxa1 3.Nxe6[] Qxc3+ 4.Kxc3[] dxe6 5.Kb2 Bd7 6.Qg3 Bc6 7.Be2 Nd7 8.Rd1 Be7 9.Bd4 Rg8 10.Qe3 b6 11.Bf3 Rc8 12.e5 Ba4 13.Bc3 Kf8 14.Be4
  +-  (1.49)   Depth: 18   00:00:41  16459kN
1.Qxg4 Qxb2 2.Kd2[] Qxa1 3.Nxe6[] Qxc3+ 4.Kxc3[] dxe6 5.Kb2 Bd7 6.Bc4 Nc6 7.Qg3 Rc8 8.Rd1 h5 9.Be2 g6 10.c3 h4 11.Qg5 h3
  +-  (1.60)   Depth: 19   00:02:16  51935kN
1.Qxg4 Qxb2[] 2.Kd2[] Qxa1 3.Nxe6[] Qxc3+ 4.Kxc3[] dxe6 5.Kb2 Bd7 6.Bc4 Nc6 7.Qg3 Rc8 8.Rd1
  +-  (1.60)   Depth: 20   00:03:22  78087kN
1.Qxg4
  +-  (1.72 !)   Depth: 21   00:07:13  161mN

This was a fresh engine instance.  I don't understand the truncated output for the last ply.  I had only seen that when Rybka was pulling from hash.
Parent - - By dragon49 (****) [us] Date 2010-07-21 01:07
New game
rnb1kb1r/pp1p1ppp/1q2p3/8/3NP1n1/2N1B3/PPP2PPP/R2QKB1R w KQkq - 0 1


Analysis by Zappa Mexico II 64:

1.Rb1 Nxe3 2.fxe3 Bb4 3.Bc4 Bxc3+ 4.bxc3 Qc5
  =  (0.15)   Depth: 9/30   00:00:00  790kN
1.Bc1 Bb4 2.a3 Bxc3+ 3.bxc3 Qc5 4.Bd2 Nf6
  =  (0.24)   Depth: 9/31   00:00:00  1401kN
1.Bc1 Bb4 2.a3 Bxc3+ 3.bxc3 Qc5 4.Bd2
  =  (0.24)   Depth: 9/31   00:00:00  1554kN
1.Bc1 Bb4 2.a3 Bc5 3.Na4 Qa5+ 4.c3 Bxd4 5.Qxd4
  =  (0.18)   Depth: 10/31   00:00:00  1780kN
1.Bc4 Qxb2 2.Ndb5 Nxe3 3.fxe3 Qb4 4.Qd3 Na6
  =  (0.22)   Depth: 10/39   00:00:01  3231kN
1.Bc4 Qxb2 2.Ndb5 Nxe3 3.fxe3 Qb4 4.Qd3
  =  (0.22)   Depth: 10/39   00:00:01  3737kN
1.Bc4 Qxb2 2.Ndb5 Nxe3 3.fxe3 Qb4 4.Qd3 Nc6 5.Rb1 Qa5 6.0-0
  =  (-0.06)   Depth: 11/40   00:00:02  4613kN
1.Rb1 Bb4 2.Qd2 Nxe3 3.fxe3 e5 4.Ndb5 Bxc3 5.Qxc3
  =  (0.13)   Depth: 11/40   00:00:02  5900kN
1.a3 Nxe3 2.fxe3 Nc6 3.Be2 Be7 4.0-0 Bg5 5.Kf2
  =  (0.24)   Depth: 11/41   00:00:03  7601kN
1.Be2 Nxe3 2.fxe3 Nc6 3.Qd2 Nxd4 4.exd4 Qxb2 5.Rb1 Qa3 6.Nb5 Qxa2
  +/=  (0.36)   Depth: 11/41   00:00:03  9309kN
1.Be2 Nxe3 2.fxe3 Nc6 3.Qd2 Nxd4 4.exd4 Qxb2 5.Rb1 Qa3 6.Nb5 Qxa2
  +/=  (0.36)   Depth: 11/41   00:00:03  10007kN
1.Be2 Nxe3 2.fxe3 Qxb2 3.Ndb5 Bb4 4.0-0 Bxc3 5.Rb1 Qxa2 6.Nxc3 Qa5 7.Nb5 0-0
  +/=  (0.31)   Depth: 12/41   00:00:04  12256kN
1.Be2 Nxe3 2.fxe3 Qxb2 3.Ndb5 Bb4 4.0-0 Bxc3 5.Rb1 Qxa2 6.Nxc3 Qa5 7.Nb5 0-0
  +/=  (0.31)   Depth: 12/41   00:00:05  14959kN
1.Be2 Nxe3 2.fxe3 Qxb2 3.Ndb5 Bb4 4.0-0 Bxc3 5.Rb1 Qxa2 6.Nxc3 Qa5 7.Nb5 0-0 8.Qd6 Nc6
  +/=  (0.36)   Depth: 13/41   00:00:06  17435kN
1.Be2 Nxe3 2.fxe3 Qxb2 3.Ndb5 Bb4 4.0-0 Bxc3 5.Rb1 Qxa2 6.Nxc3 Qa5 7.Nb5 0-0 8.Qd6 Nc6
  +/=  (0.36)   Depth: 13/45   00:00:09  23989kN
1.Be2 Nxe3 2.fxe3 Qxb2 3.Ncb5 Qb4+ 4.Qd2 Qxd2+ 5.Kxd2 Na6 6.e5 f6 7.Nd6+ Ke7 8.Rhf1
  +/=  (0.27)   Depth: 14/45   00:00:12  32157kN
1.Be2 Nxe3 2.fxe3 Qxb2 3.Ncb5 Qb4+ 4.Qd2 Qxd2+ 5.Kxd2 Na6 6.e5 f6 7.Nd6+ Ke7 8.Rhf1
  +/=  (0.27)   Depth: 14/47   00:00:22  62583kN
1.Be2 Nxe3 2.fxe3 Qxb2 3.Ncb5 Qb4+ 4.Kf2 Na6 5.Rb1 Qc5 6.Nb3 Qc6 7.e5 Qe4
  =  (0.07)   Depth: 15/47   00:00:25  71484kN
1.Bc1 Bc5 2.Na4 Qa5+ 3.c3 Bxd4 4.Qxd4 Nf6 5.Bf4 Nc6 6.Qc4 e5 7.Bg5
  =  (0.20)   Depth: 15/47   00:00:30  88985kN
1.Qxg4 Qxb2 2.Kd2 Qxa1 3.Nxe6 Bb4 4.Nc7+ Kd8 5.N7d5 Bxc3+ 6.Nxc3 Rg8 7.Qh4+ f6 8.Qxh7 Re8 9.Qxg7
  +-  (1.87)   Depth: 15/49   00:00:49  144mN
1.Qxg4 Qxb2 2.Kd2 Qxa1 3.Nxe6 Bb4 4.Nc7+ Kd8 5.N7d5 Bxc3+ 6.Nxc3 Rg8 7.Qh4+ f6 8.Qxh7 Re8 9.Qxg7
  +-  (1.87)   Depth: 15/49   00:00:52  150mN
1.Qxg4 Qxb2 2.Kd2 Qxa1 3.Nxe6 Nc6 4.Nc7+ Kd8 5.Nxa8 f6 6.Nd5 Qxa2 7.Qg3 Qa5+ 8.Ke2 Ne5 9.Nac7 b6 10.f4 Nc4
  +-  (2.05)   Depth: 16/51   00:02:11  376mN
1.Qxg4 Qxb2 2.Kd2 Qxa1 3.Nxe6 Nc6 4.Nc7+ Kd8 5.Nxa8 f6 6.Nd5 Qxa2 7.Qg3 Qa5+ 8.Ke2 Ne5 9.Nac7 b6 10.f4 Nc4
  +-  (2.05)   Depth: 16/51   00:02:16  388mN
1.Qxg4 Qxb2 2.Kd2 Qxa1 3.Nxe6 Nc6 4.Nc7+ Kd8 5.Nxa8 f6 6.Nd5 Qxa2 7.Nac7 Qa5+ 8.c3 Qa2+ 9.Ke1 b6 10.Qd1 Bb7 11.Be2 Ne7 12.Kf1 Nxd5 13.Nxd5
  +-  (2.11)   Depth: 17/53   00:03:59  690mN
1.Qxg4 Qxb2 2.Kd2 Qxa1 3.Nxe6 Nc6 4.Nc7+ Kd8 5.Nxa8 f6 6.Nd5 Qxa2 7.Nac7 Qa5+ 8.c3 Qa2+ 9.Ke1 b6 10.Qd1 Bb7 11.Be2 Ne7 12.Kf1 Nxd5 13.Nxd5
  +-  (2.11)   Depth: 17/53   00:04:09  718mN
1.Qxg4 Qxb2 2.Kd2 Qxa1 3.Nxe6 Nc6 4.Nc7+ Kd8 5.Nxa8 f6 6.Nd5 Qb1 7.a3 Bxa3 8.Qxg7 Qc1+ 9.Ke2 Qxc2+ 10.Kf3 Rf8 11.Nab6 Rf7 12.Qg8+ Rf8 13.Qxh7 Bd6 14.Nxc8
  +-  (1.98)   Depth: 18/55   00:06:33  1151mN
1.Qxg4 Qxb2 2.Kd2 Qxa1 3.Nxe6 Nc6 4.Nc7+ Kd8 5.Nxa8 f6 6.Nd5 Qb1 7.a3 Bxa3 8.Qxg7 Qc1+ 9.Ke2 Qxc2+ 10.Kf3 Rf8 11.Nab6 Rf7 12.Qg8+ Rf8 13.Qxh7 Bd6 14.Nxc8
  +-  (1.98)   Depth: 18/55   00:06:59  1227mN
1.Qxg4 Qxb2 2.Kd2 h5 3.Qd1 Qb6 4.Rb1 Qd8 5.f4 a6 6.Ke2 b5 7.Kf2 Bc5 8.Qd2 d6 9.Nf3 Nd7 10.a4 Bxe3+ 11.Qxe3
  +-  (2.06)   Depth: 19/57   00:21:13  3743mN
1.Qxg4 Qxb2 2.Kd2 h5 3.Qd1 Qb6 4.Rb1 Qd8 5.f4 a6 6.Ke2 b5 7.Kf2 Bc5 8.Qd2 d6 9.Nf3 Nd7 10.a4 Bxe3+ 11.Qxe3
  +-  (2.06)   Depth: 19/57   00:22:00  3880mN
Parent - - By dragon49 (****) [us] Date 2010-07-21 01:24
New game
rnb1kb1r/pp1p1ppp/1q2p3/8/3NP1n1/2N1B3/PPP2PPP/R2QKB1R w KQkq - 0 1


Analysis by Critter 0.70 64-bit:

1.Bc1 Nc6 2.Qxg4 Nxd4 3.Bd3 h5 4.Qg5
  =  (0.14)   Depth: 6/9   00:00:00  10kN
1.Bc1 Nc6 2.Qxg4 Nxd4 3.Bd3 h5 4.Qg5 Qc5 5.h4 Qxg5 6.Bxg5
  =  (0.16)   Depth: 7/11   00:00:00  14kN
1.Bc1 Nc6 2.Qxg4 Nxd4 3.Bd3 h5 4.Qg5 Qc5 5.h4 Qxg5 6.Bxg5
  =  (0.04 --)   Depth: 8/13   00:00:00  46kN
1.Bc1 Bb4 2.h3 Bxc3+ 3.bxc3 Nf6 4.Qd3 Nc6 5.Nb5
  =  (0.08)   Depth: 8/13   00:00:00  52kN
1.Bc1 Bb4 2.h3 Bxc3+ 3.bxc3 Nf6 4.Qd3 Nc6 5.Nb5
  =  (-0.03 --)   Depth: 9/25   00:00:00  214kN
1.Bc1 Bb4 2.h3 Nf6 3.Qd3 Nc6 4.Nxc6 Qxc6 5.Bd2 0-0 6.e5
  =  (-0.01)   Depth: 9/25   00:00:00  259kN
1.Bg5 Bc5 2.Ncb5 a6 3.Qxg4 axb5 4.c3 Bxd4 5.cxd4 Qxd4 6.Rc1 Nc6
  =  (-0.06)   Depth: 10/25   00:00:00  565kN
1.Bc1 Bb4 2.h3 Qc5 3.Qd2 Nf6 4.f3 0-0 5.a3 Bxc3 6.Qxc3 Qxc3+ 7.bxc3 Nc6 8.Kf2
  =  (-0.14)   Depth: 11/25   00:00:00  1090kN
1.Bc1 Bb4 2.h3 Qc5 3.Qd2 Nf6 4.Nb3 Nxe4 5.Nxc5 Nxd2 6.Nxe6 Nf3+ 7.Ke2 fxe6 8.Kxf3 Nc6 9.Kg4 Bxc3 10.bxc3 h5+ 11.Kg3
  =  (-0.03 !)   Depth: 12/30   00:00:00  1918kN
1.Bc1 Bb4 2.h3 Qc5 3.Qd3 Ne5 4.Qe3 0-0 5.Ndb5 Nbc6 6.a3 Bxc3+ 7.Qxc3 Qxc3+ 8.Nxc3 Nd4 9.Kd2 d6 10.Be2 Nxe2 11.Kxe2
  =  (-0.02)   Depth: 12/30   00:00:00  2187kN
1.Bc1 Bb4 2.h3 Qc5 3.Qd3 Ne5 4.Qe3 0-0 5.Ndb5 Nbc6 6.a3 Bxc3+ 7.Qxc3 Qxc3+ 8.Nxc3 Nd4 9.Kd2 d6 10.Be2 Nxe2 11.Kxe2
  =  (-0.02)   Depth: 13/30   00:00:00  2641kN
1.Bc1 Bb4 2.h3 Nf6 3.Qd3 Nc6 4.Nxc6 bxc6 5.Be3 Qa5 6.Bd2 0-0 7.Qg3 d5 8.Bd3
  =  (0.09 !)   Depth: 14/30   00:00:01  4743kN
1.Bc1 Bb4 2.Qxg4 Qxd4 3.Bd2 Nc6 4.0-0-0 0-0 5.Qg3 Bd6 6.Bf4 Bxf4+ 7.Qxf4 Qc5 8.Kb1 f5 9.Qd2 fxe4 10.Nxe4 Qf5 11.f3
  =  (0.14)   Depth: 14/34   00:00:01  6806kN
1.Qxg4 Qxb2 2.Rb1 Qxc3+ 3.Kd1
  +/=  (0.26 !)   Depth: 15/49   00:00:03  16040kN
1.Qxg4 Qxb2 2.Rb1 Qxc3+ 3.Kd1
  +/=  (0.38 !)   Depth: 15/49   00:00:03  17033kN
1.Qxg4 Qxb2 2.Rb1 Qxc3+ 3.Kd1
  +/=  (0.55 !)   Depth: 15/49   00:00:03  18391kN
1.Qxg4 Qxb2 2.Rb1 Qxc3+ 3.Kd1
  +/-  (0.82 !)   Depth: 15/49   00:00:04  20981kN
1.Qxg4 Qxb2 2.Rb1 Qxc3+ 3.Kd1
  +/-  (1.21 !)   Depth: 15/58   00:00:06  29854kN
1.Qxg4 Qxb2 2.Rb1 Qxc3+ 3.Kd1
  +-  (1.79 !)   Depth: 15/63   00:00:08  42331kN
1.Qxg4 Qxb2 2.Kd2 Qxa1 3.Nxe6 Bb4 4.Nxg7+ Kf8 5.Bd4 Nc6 6.Nh5 Rg8 7.Bg7+ Rxg7 8.Qxg7+ Ke7 9.Qf6+ Kf8 10.Qh8+ Ke7 11.Nf4 Bxc3+ 12.Qxc3 Qxc3+ 13.Kxc3 Kd6 14.Bd3 Rb8 15.Rb1 b6 16.Nd5 Bb7 17.Be2 Re8 18.Rd1
  +-  (1.92)   Depth: 15/63   00:00:10  53048kN
1.Qxg4 Qxb2 2.Kd2 Qxa1 3.Nxe6 Bb4 4.Nxg7+ Kf8 5.Bd4 Nc6 6.Nh5 Rg8 7.Bg7+ Rxg7 8.Qxg7+ Ke7 9.Qf6+ Kf8 10.Qh8+ Ke7 11.Nf4 Bxc3+ 12.Qxc3 Qxc3+ 13.Kxc3 Kd6 14.Bd3 Rb8 15.Rb1 b6 16.Nd5 Bb7 17.Be2 Re8 18.Rd1
  +-  (1.81 --)   Depth: 16/63   00:00:12  58494kN
1.Qxg4 Qxb2 2.Kd2 Qxa1 3.Nxe6 Bb4 4.Nxg7+ Kf8 5.Bd4 Nc6 6.Nh5 Rg8 7.Bg7+ Rxg7 8.Qxg7+ Ke7 9.Qf6+ Kf8 10.Qh8+ Ke7 11.Nf4 Bxc3+ 12.Qxc3 Qxc3+ 13.Kxc3 d6 14.Nd5+ Kd8 15.Bd3 Be6 16.Rb1 Rb8 17.a3 Ne5 18.Nf6 h6 19.Kd4 Kc7 20.Be2 Rc8
  +-  (1.87)   Depth: 16/63   00:00:12  62393kN
1.Qxg4 Qxb2 2.Kd2 Qxa1 3.Nxe6 Bb4 4.Nxg7+ Kf8 5.Bd4 Nc6 6.Nh5 Rg8 7.Bg7+ Rxg7 8.Qxg7+ Ke7 9.Qf6+ Kf8 10.Qh8+ Ke7 11.Nf4 Bxc3+ 12.Qxc3 Qxc3+ 13.Kxc3 d6 14.Nd5+ Kd8 15.Bd3 Be6 16.Rb1 Rb8 17.a3 Ne5 18.Nf6 h6 19.Kd4 Kc7 20.Be2 Rc8
  +-  (1.87)   Depth: 17/63   00:00:14  71847kN
1.Qxg4 Qxb2 2.Kd2 Qxa1 3.Nxe6 Bb4 4.Nxg7+ Kf8 5.Bd4 Nc6 6.Nh5 Rg8 7.Bg7+ Rxg7 8.Qxg7+ Ke7 9.Qf6+ Kf8 10.Qh8+ Ke7 11.Nf4 Bxc3+ 12.Qxc3 Qxc3+ 13.Kxc3 d6 14.Nd5+ Kd8 15.Bd3 Be6 16.Rb1 Rb8 17.a3 Ne5 18.Nf6 Ng4 19.Nxg4 Bxg4 20.f3 Rc8+ 21.Kd4
  +-  (1.87)   Depth: 18/63   00:00:19  97896kN
1.Qxg4 Qxb2 2.Kd2 Qxa1 3.Nxe6 Bb4 4.Nxg7+ Kf8 5.Bd4 Nc6 6.Nh5 Rg8 7.Bg7+ Rxg7 8.Qxg7+ Ke7 9.Qf6+ Kf8 10.Qh8+ Ke7 11.Nf4 Bxc3+ 12.Qxc3 Qxc3+ 13.Kxc3 d6 14.Nd5+ Kf8 15.Bc4 Ne5 16.Nc7 Rb8 17.Rd1 f5 18.exf5 Nxc4 19.Kxc4 Bxf5 20.Rxd6 Bxc2 21.Rd7 Bf5
  +-  (1.99 !)   Depth: 19/63   00:00:28  146mN
1.Qxg4 Qxb2 2.Kd2 Qxa1 3.Nxe6 Bb4 4.Nxg7+ Kf8 5.Bd4 Nc6 6.Nh5 Rg8 7.Bg7+ Rxg7 8.Qxg7+ Ke7 9.Qf6+ Kf8 10.Bc4 Bxc3+ 11.Qxc3 Qxc3+ 12.Kxc3 Na5 13.Bd5 Ke7 14.Nf4 d6 15.Rb1 Be6 16.Kb4 Nc6+ 17.Ka4 Bc8 18.c3 Nd8 19.Kb3 Nc6
  +-  (2.11 !)   Depth: 19/63   00:00:42  226mN
1.Qxg4 Qxb2 2.Kd2 Qxa1 3.Nxe6 Bb4 4.Nxg7+ Kf8 5.Bd4 Nc6 6.Nh5 Rg8 7.Bg7+ Rxg7 8.Qxg7+ Ke7 9.Qf6+ Kf8 10.Bc4 Bxc3+ 11.Qxc3 Qxc3+ 12.Kxc3 Na5 13.Bd5 Ke7 14.Rb1 d6 15.Rb5 Nc6 16.Nf4 Kf6 17.Rb1 Kg5 18.Ne2 Kg6 19.Nd4 Nxd4 20.Kxd4
  +-  (2.28 !)   Depth: 19/63   00:00:49  265mN
1.Qxg4 Qxb2 2.Kd2 Qxa1 3.Nxe6 Bb4 4.Nxg7+ Kf8 5.Bd4 Nc6 6.Nh5 Rg8 7.Bg7+ Rxg7 8.Qxg7+ Ke7 9.Qf6+ Kf8 10.Bc4
  +-  (2.55 !)   Depth: 19/63   00:01:00  325mN
1.Qxg4
  +-  (2.94 !)   Depth: 19/67   00:02:02  656mN
1.Qxg4 Qxb2 2.Kd2 h5 3.Qd1 Qb6 4.Rb1
  +-  (2.80)   Depth: 19/67   00:03:19  1082mN
1.Qxg4 Qxb2 2.Kd2 h5 3.Qd1 Qb6 4.Rb1 Qd8 5.Rb5 g6 6.Kc1 Bg7 7.Be2 0-0
  +-  (2.82)   Depth: 20/67   00:03:51  1262mN
1.Qxg4
  +-  (2.93 !)   Depth: 21/67   00:06:05  1990mN
1.Qxg4
  +-  (3.05 !)   Depth: 21/67   00:08:26  2773mN
1.Qxg4 Qxb2 2.Kd2 h5 3.Qd1 Qb6 4.Ndb5
  +-  (3.08)   Depth: 21/75   00:12:42  4197mN
1.Qxg4 Qxb2 2.Kd2 h5 3.Qd1 Qb6 4.Ndb5
  +-  (2.96 --)   Depth: 22/75   00:13:44  4513mN
1.Qxg4 Qxb2 2.Kd2 Qxa1 3.Nxe6 Qxc3+ 4.Kxc3 dxe6 5.Kb2 Bd7
  +-  (2.94)   Depth: 22/75   00:16:12  5327mN
Parent - - By dragon49 (****) [us] Date 2010-07-21 01:29
Fritz12 - single core 32 bit

New game
rnb1kb1r/pp1p1ppp/1q2p3/8/3NP1n1/2N1B3/PPP2PPP/R2QKB1R w KQkq - 0 1


Analysis by Fritz 12:

1.Bf4 Qxb2 2.Ncb5 Bc5 3.Be2 e5 4.Bxg4 exf4 5.0-0 0-0
  =  (0.19)   Depth: 10/35   00:00:00  618kN
1.Bf4 Nc6 2.Ncb5 e5 3.Qxg4 Nxd4 4.Bxe5 Nxb5 5.0-0-0 d6 6.Qg5
  -/+  (-1.25)   Depth: 11/31   00:00:00  1047kN
1.Rb1 Nxe3 2.fxe3 Be7 3.Bb5 a6 4.Bc4 Nc6 5.0-0 Bg5 6.Qd3 Bxe3+ 7.Qxe3 Nxd4
  =  (-0.02)   Depth: 11/31   00:00:00  1192kN
1.Rb1 Nxe3 2.fxe3 Be7 3.Bb5 a6 4.Be2 Nc6 5.0-0 Bg5 6.Qd3 Bxe3+ 7.Qxe3 Nxd4
  =  (-0.08)   Depth: 12/29   00:00:00  1872kN
1.Nd5 exd5 2.Qxg4 Qxb2 3.Rd1 h5 4.Qf5 Bb4+ 5.Ke2 Nc6 6.Qxd5 d6 7.Nf5 Bxf5
  =  (-0.03)   Depth: 12/30   00:00:01  3060kN
1.Qd2 Nxe3 2.fxe3 Qxb2 3.Rb1 Qa3 4.Be2 Bb4 5.Rb3 Qa5 6.0-0 0-0 7.Bb5
  =  (0.09)   Depth: 12/37   00:00:01  3836kN
1.Na4 Qa5+ 2.Bd2 Qxa4 3.Bc3 Bc5 4.Bb5 Nxf2 5.Bxa4 Nxd1 6.Rxd1 Nc6 7.Nxc6 dxc6 8.Bxg7
  +/=  (0.35)   Depth: 12/37   00:00:01  4419kN
1.Na4 Qa5+ 2.Bd2 Qxa4 3.Bc3 Bc5 4.Bb5 Nxf2 5.Bxa4 Nxd1 6.Rxd1 Na6 7.0-0 Nb4
  =  (0.11)   Depth: 13/30   00:00:01  4673kN
1.Na4 Qa5+ 2.Bd2 Qxa4 3.Bc3 Bc5 4.Bb5 Nxf2 5.Bxa4 Nxd1 6.Rxd1 Na6 7.Nb5 0-0 8.Nd6
  +/=  (0.33)   Depth: 14/30   00:00:02  6882kN
1.Na4 Qa5+ 2.Bd2 Qxa4 3.Bc3 Bc5 4.Bb5 Nxf2 5.Bxa4 Nxd1 6.Rxd1 Na6 7.Ke2 Ke7 8.Nb3 f6
  =  (0.21)   Depth: 15/32   00:00:03  8901kN
1.Na4 Qa5+ 2.Bd2 Qxa4 3.Bc3 Bc5 4.Bb5 Nxf2 5.Bxa4 Nxd1 6.Rxd1 Na6 7.Rf1 Nb4 8.a3 e5 9.axb4
  =  (0.17)   Depth: 16/36   00:00:05  13765kN
1.Qxg4 Qxb2 2.Kd2 Qxa1 3.Nxe6 Bb4 4.Nc7+ Kd8 5.N7d5 Bxc3+ 6.Nxc3 Rg8 7.Qh4+ Ke8 8.Qxh7 Rf8 9.Qxg7 Nc6 10.Bc5
  +-  (2.47)   Depth: 16/44   00:00:12  32428kN
1.Qxg4 Qxb2 2.Kd2 Qxa1 3.Nxe6 Qxc3+ 4.Kxc3 dxe6 5.Bb5+ Bd7 6.Qg5 h6 7.Qh5 Be7 8.Rd1 a6 9.Bc4 0-0 10.Bd4
  +-  (3.57)   Depth: 17/45   00:00:21  55600kN
1.Qxg4 Qxb2 2.Kd2 Qxa1 3.Nxe6 Qxc3+ 4.Kxc3 dxe6 5.Qg3 Nc6 6.Bb5 Bd7 7.Rd1 Rc8 8.Kb2 a6 9.Be2 Nb4 10.c3
  +-  (3.62)   Depth: 18/47   00:00:31  80808kN
1.Qxg4 Qxb2 2.Kd2 Qxa1 3.Nxe6 Qxc3+ 4.Kxc3 dxe6 5.Bb5+ Bd7 6.Qg5 h6 7.Qh5 Be7 8.Rd1 a6 9.Bc4 0-0 10.Bc5
  +-  (3.49)   Depth: 19/49   00:00:46  121mN
1.Qxg4 Qxb2 2.Kd2 Qxa1 3.Nxe6 Qxc3+ 4.Kxc3 dxe6 5.Qg3 Bd7 6.Bc4 Nc6 7.Rd1 0-0-0 8.h3 Be8 9.Rxd8+ Kxd8 10.Bd4 Bb4+ 11.Kb2 Nxd4
  +-  (3.37)   Depth: 20/49   00:01:10  182mN
1.Qxg4 Qxb2 2.Kd2 Qxa1 3.Nxe6 Qxc3+ 4.Kxc3 dxe6 5.Qg3 Bd7 6.Bc4 Nc6 7.Rd1 0-0-0 8.Kb2 Be8 9.Rxd8+ Kxd8 10.Bf4 Kc8 11.Qc3
  +-  (3.28)   Depth: 21/51   00:01:58  305mN
1.Qxg4 Qxb2 2.Kd2 Qxa1 3.Nxe6 Qxc3+ 4.Kxc3 dxe6 5.Qg3 Bd7 6.Be2 Nc6 7.Rd1 0-0-0 8.Bf4 Bb4+ 9.Kb2 e5 10.Bxe5 Nxe5 11.Qxe5 Rhe8 12.Qd4
  +-  (3.40)   Depth: 22/55   00:03:42  579mN
Parent - - By dragon49 (****) [us] Date 2010-07-21 01:34
bright 0-3a (4 cores but 32 bit)

New game
rnb1kb1r/pp1p1ppp/1q2p3/8/3NP1n1/2N1B3/PPP2PPP/R2QKB1R w KQkq - 0 1


Analysis by bright-0.3a:

1.Bc1 Nc6 2.Qxg4 Nxd4 3.Bd3 d5 4.exd5 exd5
  +/-  (0.73)   Depth: 6/18   00:00:00  33kN
1.Bc1 Nf6 2.Ndb5 Bc5 3.Qf3 a6 4.Na4 Qa5+ 5.Nbc3
  +/=  (0.47)   Depth: 7/18   00:00:00  88kN
1.Bc1 Nf6 2.Qd2 Nc6 3.Ndb5 Ne5 4.Qd4 Qxd4 5.Nxd4
  +/=  (0.42)   Depth: 8/22   00:00:00  260kN
1.Bc1 Nf6 2.Ndb5 Bc5 3.Qf3 a6 4.e5 axb5 5.exf6
  =  (0.17)   Depth: 9/24   00:00:00  545kN
1.Bc1 Nf6 2.Ndb5 Bc5 3.Qf3 a6 4.e5 Ng4 5.Nd6+ Bxd6 6.exd6
  +/=  (0.37)   Depth: 10/24   00:00:00  1273kN
1.Bc1 Nf6 2.Ndb5 Bc5 3.Qf3 a6 4.e5 Ng4 5.Nd6+ Bxd6 6.exd6 Ne5 7.Qg3
  +/=  (0.30)   Depth: 11/26   00:00:00  2372kN
1.Bc1 Bb4 2.Qxg4 Qxd4 3.Bd2 Nc6 4.Be2 d5 5.exd5 exd5 6.Qxd4 Nxd4 7.Bd3
  +/=  (0.34)   Depth: 12/38   00:00:01  7132kN
1.Bc1 Bb4 2.Qxg4 Qxd4 3.Bd2 Nc6 4.Be2 d5 5.exd5 exd5 6.Qxd4 Nxd4 7.Bd3 0-0 8.0-0
  +/=  (0.31)   Depth: 13/39   00:00:02  15619kN
1.Bc1 Bc5 2.Na4 Qa5+ 3.c3 Bxd4 4.Qxd4 0-0 5.Nc5 Nc6 6.Qd6 b6 7.Nxd7 Rd8 8.Qxc6 Bxd7 9.Qc7
  =  (0.20)   Depth: 14/49   00:00:08  50511kN
1.Qxg4 Qxb2 2.Kd2 Qxa1 3.Nxe6 Bb4 4.Nc7+ Kd8 5.N7d5 Bxc3+ 6.Nxc3 Rg8 7.Qh4+ f6 8.Qxh7 Re8 9.Qxg7
  +-  (1.54)   Depth: 14/49   00:00:11  68573kN
1.Qxg4 Qxb2 2.Kd2 Qxa1 3.Nxe6 Qxc3+ 4.Kxc3 dxe6 5.Bc4 Nc6 6.Rd1 g6 7.Kb2 Bg7+ 8.c3 0-0 9.f4
  +-  (1.72)   Depth: 15/49   00:00:14  86326kN
1.Qxg4 Qxb2 2.Kd2 Qxa1 3.Nxe6 Qxc3+ 4.Kxc3 dxe6 5.Bc4 Nc6 6.Rd1 g6 7.f4 Bg7+ 8.e5 0-0 9.Kb2 b6 10.a3
  +-  (1.80)   Depth: 16/54   00:00:19  118mN
1.Qxg4 Qxb2 2.Kd2 Qxa1 3.Nxe6 Qxc3+ 4.Kxc3 dxe6 5.Bc4 Nc6 6.Rd1 a6 7.f4 b5 8.Be2 Bb4+ 9.Kb2 0-0 10.Qg5
  +-  (1.69)   Depth: 17/54   00:00:26  171mN
1.Qxg4 Qxb2 2.Kd2 Qxa1 3.Nxe6 Qxc3+ 4.Kxc3 dxe6 5.Qg3 Nc6 6.Bb5 Bd7 7.Rd1 Rc8 8.Kb2 a6 9.Be2 Na5 10.Bd4
  +-  (1.71)   Depth: 18/58   00:00:46  297mN
1.Qxg4 Qxb2 2.Kd2 Qxa1 3.Nxe6 Qxc3+ 4.Kxc3 dxe6 5.Qg3 Bd7 6.Be2 Nc6 7.Rd1 0-0-0 8.Kb2 e5 9.Bg4 h5 10.Bf5 Bxf5 11.Rxd8+ Kxd8 12.exf5
  +-  (1.76)   Depth: 19/62   00:01:36  613mN
1.Qxg4 Qxb2 2.Kd2 Qxa1 3.Nxe6 Qxc3+ 4.Kxc3 dxe6 5.Qg3 Bd7 6.Be2 Nc6 7.Rd1 0-0-0 8.Kb2 e5 9.Bg4 h5 10.Bxd7+ Rxd7 11.Rxd7 Kxd7 12.c3
  +-  (1.81)   Depth: 20/68   00:03:20  1261mN
Parent - - By dcorbit (***) [us] Date 2010-07-21 20:12
These two solved in one second:
Analysis from Q:\qxg4.epd  
7/21/2010 12:10:28 PM Level: Blitz 1/1
Analyzing engine: Houdini_x64_4CPU

1) Qxg4;               
    Searching move: Qd1xg4
    Best move (Houdini_x64_4CPU): Qd1xg4
    identical moves! Found in: 00:01
     4/19  00:00         5.144  1.286.000  +0.14  Be3c1 Nb8c6 Qd1xg4 Nc6xd4 Bf1d3 d7d5 e4xd5 e6xd5
     4/19  00:00         5.594  1.398.000  +0.17  Be3f4 Qb6xb2 Nd4b5 Nb8a6 Bf1e2
     5/19  00:00         6.773  1.354.000  +0.17  Be3f4 Qb6xb2 Nd4b5 Nb8a6 Bf1e2
     6/21  00:00        16.140  1.467.000  -0.14  Be3f4 Qb6xb2 Bf4d2 Qb2b6 Nc3b5 Nb8c6 Qd1xg4 Nc6xd4
     6/21  00:00        17.139  1.428.000  +0.24  Be3c1 Nb8c6 Qd1xg4 Nc6xd4 Bf1d3 d7d5 OO e6e5
     7/21  00:00        20.128  1.258.000  +0.24  Be3c1 Nb8c6 Qd1xg4 Nc6xd4 Bf1d3 d7d5 OO e6e5
     8/21  00:00        31.988  1.332.000  +0.17  Be3c1 Nb8c6 Qd1xg4 Nc6xd4 Bf1d3 d7d5 OO e6e5 Qg4g5
     9/21+  00:00        39.055  1.394.000  +0.23  Be3c1 Nb8c6 Qd1xg4 Nc6xd4 Bf1d3 d7d5 OO e6e5 Qg4g5 f7f6 Qg5h5+ g7g6
     9/21+  00:00        56.274  1.563.000  +0.35  Be3c1 Nb8c6 Qd1xg4 Nc6xd4 Bf1d3 d7d5 OO e6e5 Qg4g5 f7f6 Qg5h5+ g7g6
     9/29  00:00        90.088  1.732.000  +0.29  Be3c1 Nb8c6 Qd1xg4 Nc6xd4 Bf1d3 d7d6 OO Bc8d7 Rf1e1 e6e5 Qg4g5 h7h6 Qg5h5
    10/29  00:00       123.810  1.847.000  +0.29  Be3c1 Nb8c6 Qd1xg4 Nc6xd4 Bf1d3 d7d6 OO Bc8d7 Rf1e1 e6e5 Qg4g5 h7h6 Qg5h5
    11/29  00:00       160.064  2.026.000  +0.29  Be3c1 Nb8c6 Qd1xg4 Nc6xd4 Bf1d3 d7d6 OO Bc8d7 Rf1e1 e6e5 Qg4g5 h7h6 Qg5h5
    12/36  00:00       903.030  2.913.000  +0.14  Be3c1 Bf8c5 Nc3a4 Qb6a5+ c2c3 Bc5xd4 Qd1xd4 OO Na4c5 b7b6 Nc5b3 Qa5h5 Bf1e2 Bc8a6 c3c4 Nb8c6 Qd4d1 Nc6e5 h2h3 f7f5 e4xf5 e6xf5 Qd1d5+ Kg8h8
    13/36+  00:00       938.338  2.923.000  +0.20  Be3c1 Bf8c5 Nc3a4 Qb6a5+ c2c3 Bc5xd4 Qd1xd4 OO Na4c5 b7b6 Nc5b3 Qa5h5 Bf1e2 Bc8a6 c3c4 Nb8c6 Qd4d1 Nc6e5 h2h3 f7f5 e4xf5 e6xf5 Qd1d5+ Kg8h8 OO
    13/39  00:00       993.897  2.940.000  +0.26  Be3c1 Bf8c5 Nc3a4 Qb6a5+ c2c3 Bc5xd4 Qd1xd4 OO Na4c5 b7b6 Nc5b3 Qa5h5 Bf1e2 Qh5g6 f2f3 Nb8c6 Qd4d6 Ng4e5 OO Bc8b7 Bc1e3
    14/39  00:00     1.421.763  3.117.000  +0.23  Be3c1 Nb8c6 Qd1xg4 Nc6xd4 Bf1d3 g7g6 OO Bf8g7 Nc3d1 d7d6 c2c3 Nd4c6 Bc1e3 Nc6e5 Qg4h4 Qb6c6 Bd3e2 b7b5 b2b3
    15/39  00:00     2.426.669  3.347.000  +0.25  Be3c1 Nb8c6 Qd1xg4 Nc6xd4 Bf1d3 g7g6 a2a4 Bf8g7 Nc3b5 Nd4xb5 a4xb5 d7d5 OO OO Bc1e3 d5d4 Be3d2 Bc8d7 Bd2b4 Rf8c8
    16/39  00:01     3.506.930  3.517.000  +0.25  Be3c1 Nb8c6 Qd1xg4 Nc6xd4 Bf1d3 g7g6 a2a4 Bf8g7 Nc3b5 Nd4xb5 a4xb5 d7d5 OO OO Bc1e3 d5d4 Be3d2 Bc8d7 Bd2b4 Rf8c8
    16/43+  00:01     6.148.699  3.879.000  +0.32  Qd1xg4 Qb6xb2 Ra1d1 Qb2xc3+ Rd1d2 Qc3a1+ Rd2d1 Qa1xa2
    16/63+  00:05    20.880.222  3.907.000  +1.95  Qd1xg4 Qb6xb2 Ra1d1 Qb2xc3+ Rd1d2 Qc3a1+ Rd2d1 Qa1xa2
    16/63  00:06    24.049.003  3.952.000  +1.90  Qd1xg4 Qb6xb2 Ke1d2 Qb2xa1 Nd4xe6 Qa1xc3+ Kd2xc3 d7xe6 Kc3b2 Bc8d7 Bf1e2 Bd7c6 f2f3 Nb8d7 Rh1d1 Bc6a4 e4e5 Ba4c6 Qg4d4 Bf8c5 Qd4c3 Bc5xe3 Qc3xe3 OO f3f4 Ra8d8 Qe3xa7 Bc6xg2
    17/63  00:07    29.930.883  4.021.000  +1.84  Qd1xg4 Qb6xb2 Ke1d2 Qb2xa1 Nd4xe6 Qa1xc3+ Kd2xc3 d7xe6 Kc3b2 Bc8d7 Bf1e2 Bd7c6 Rh1d1 Nb8d7 Be3d4 Nd7f6 Bd4xf6 g7xf6 Qg4f4 Rh8g8 g2g3 Ra8c8 Qf4e3 a7a6 Qe3d4 e6e5 Qd4c4 b7b5 Qc4d3
    18/63  00:10    40.699.218  4.128.000  +1.84  Qd1xg4 Qb6xb2 Ke1d2 Qb2xa1 Nd4xe6 Qa1xc3+ Kd2xc3 d7xe6 Kc3b2 Bc8d7 Bf1e2 Bd7c6 Rh1d1 Nb8d7 Be3d4 Nd7f6 Bd4xf6 g7xf6 Qg4f4 Rh8g8 g2g3 Ra8c8 Qf4e3 a7a6 Qe3d4 e6e5 Qd4c4 b7b5 Qc4d3
    19/63+  00:16    66.769.126  4.212.000  +1.96  Qd1xg4 Qb6xb2 Ke1d2 Qb2xa1 Nd4xe6 Qa1xc3+ Kd2xc3 d7xe6 Kc3b2 Bc8d7 Bf1e2 Bd7c6 Rh1d1 Nb8d7 Be3d4 Nd7f6 Bd4xf6 g7xf6 Qg4f4 Rh8g8 g2g3 Ra8c8 Qf4e3 a7a6 Qe3d4 e6e5 Qd4c4 b7b5 Qc4d3
    19/63  00:18    75.400.418  4.227.000  +1.95  Qd1xg4 Qb6xb2 Ke1d2 Qb2xa1 Nd4xe6 Qa1xc3+ Kd2xc3 d7xe6 Kc3b2 Bc8d7 Qg4g3 a7a6 Qg3c7 Nb8c6 Bf1e2 Ra8c8 Qc7b6 Bf8d6 Rh1d1 Bd6c7 Qb6c5 f7f6 Qc5h5+ g7g6 Qh5h6 Bc7e5+ c2c3 Nc6e7 Be3d4 Bd7a4 Bd4xe5 Ba4xd1 Be5xf6
    20/63+  00:28   120.341.885  4.305.000  +2.06  Qd1xg4 Qb6xb2 Ke1d2 Qb2xa1 Nd4xe6 Qa1xc3+ Kd2xc3 d7xe6 Kc3b2 Bc8d7 Qg4g3 a7a6 Qg3c7 Nb8c6 Bf1e2 Ra8c8 Qc7b6 Bf8d6 Rh1d1 Bd6c7 Qb6c5 f7f6 Qc5h5+ g7g6 Qh5h6 Bc7e5+ c2c3 Nc6e7 Be3d4 Bd7a4 Bd4xe5 Ba4xd1 Be5xf6
    20/63  00:31   134.209.095  4.321.000  +1.91  Qd1xg4 Qb6xb2 Ke1d2 Qb2xa1 Nd4xe6 Qa1xc3+ Kd2xc3 d7xe6 Kc3b2 Bc8d7 Qg4g3 a7a6 Qg3c7 Nb8c6 Bf1e2 Ra8c8 Qc7b6 Bf8d6 Rh1d1 Bd6c7 Qb6c5 h7h6 f2f4 Rc8d8 e4e5 Bd7c8 Be2d3 Rd8d5 Qc5c3 Bc8d7
    21/63+  00:50   220.444.800  4.368.000  +2.03  Qd1xg4 Qb6xb2 Ke1d2 Qb2xa1 Nd4xe6 Qa1xc3+ Kd2xc3 d7xe6 Kc3b2 Bc8d7 Qg4g3 a7a6 Qg3c7 Nb8c6 Bf1e2 Ra8c8 Qc7b6 Bf8d6 Rh1d1 Bd6c7 Qb6c5 h7h6 f2f4 Rc8d8 e4e5 Bd7c8 Be2d3 Rd8d5 Qc5c3 Bc8d7
    21/63  01:08   299.048.513  4.405.000  +2.06  Qd1xg4 Qb6xb2 Ke1d2 Qb2xa1 Nd4xe6 Qa1xc3+ Kd2xc3 d7xe6 Kc3b2 Bc8d7 Bf1c4 Nb8c6 Qg4g3 g7g6 Rh1d1 Bf8g7+ Kb2b1 Bg7e5 Qg3h4 Be5g7 f2f4 b7b6 f4f5 Ra8c8 Bc4a6 Rc8c7 f5f6 Bg7f8 Ba6b5
    22/63  02:01   528.510.819  4.358.000  +2.04  Qd1xg4 Qb6xb2 Ke1d2 Qb2xa1 Nd4xe6 Qa1xc3+ Kd2xc3 d7xe6 Kc3b2 Bc8d7 Bf1c4 Nb8c6 Qg4g3 g7g6 Rh1d1 Bf8g7+ Kb2b1 OOO Be3g5 f7f6 Bg5e3 e6e5 Be3c5 Bg7f8 Bc5xf8 Rh8xf8 Bc4d5 Nc6d4 Kb1b2 Bd7c6 Bd5xc6 Nd4xc6 Qg3h3+ Kc8b8 Rd1xd8+ Rf8xd8 Qh3xh7
   7/21/2010 12:36:48 PM, Time for this analysis: 00:03:00, Rated time: 00:01

1 of 1 matching moves
7/21/2010 12:36:49 PM, Total time: 12:26:20 AM
Rated time: 00:01 = 1 Seconds

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Analysis from Q:\qxg4.epd  
7/21/2010 12:10:28 PM Level: Blitz 1/1
Analyzing engine: IvanHoe55Mod-x64

1) Qxg4;               
    Searching move: Qd1xg4
    Best move (IvanHoe55Mod-x64): Qd1xg4
    identical moves! Found in: 00:01
      2  00:00           578  0  -0.16  Qd1xg4 Qb6xb2 Ra1d1 Qb2xc3+ Rd1d2 Qc3a1+ Rd2d1 Qa1xa2
      2  00:00           743  0  +0.05  Be3f4 Qb6xb2
      2  00:00           976  0  +0.32  Be3c1 Bf8e7
      2  00:00         1.085  0  +0.32  Be3c1 Bf8e7
      3  00:00         2.416  0  +0.32  Be3c1 h7h5 h2h3 Nb8c6 h3xg4 Qb6xd4 g4xh5
      3  00:00         2.661  0  +0.32  Be3c1 h7h5 h2h3 Nb8c6 h3xg4 Qb6xd4 g4xh5
      4  00:00         4.547  0   0.00  Be3c1 Nb8c6 Qd1xg4 Nc6xd4 Bf1d3 h7h5 Qg4g5
      4  00:00         5.100  0   0.00  Be3c1 Nb8c6 Qd1xg4 Nc6xd4 Bf1d3 h7h5 Qg4g5
      5  00:00         5.962  0   0.00  Be3c1 Nb8c6 Qd1xg4 Nc6xd4 Bf1d3 h7h5 Qg4g5
      5  00:00         6.675  0   0.00  Be3c1 Nb8c6 Qd1xg4 Nc6xd4 Bf1d3 h7h5 Qg4g5
      6  00:00         7.757  0  +0.05  Be3c1 Nb8c6 Qd1xg4 Nc6xd4 Bf1d3 h7h5 Qg4g5 a7a6 e4e5 d7d5 e5xd6/ep Qb6xd6
      6  00:00         8.423  0  +0.05  Be3c1 Nb8c6 Qd1xg4 Nc6xd4 Bf1d3 h7h5 Qg4g5 a7a6 e4e5 d7d5 e5xd6/ep Qb6xd6
      7+  00:00        10.012  0  +0.13  Be3c1 Nb8c6 Qd1xg4 Nc6xd4 Bf1d3 h7h5 Qg4g5 a7a6 e4e5 d7d5 e5xd6/ep Qb6xd6
      7+  00:00        10.618  0  +0.21  Be3c1 Nb8c6 Qd1xg4 Nc6xd4 Bf1d3 h7h5 Qg4g5 a7a6 e4e5 d7d5 e5xd6/ep Qb6xd6
      7  00:00        11.476  0  +0.17  Be3c1 Nb8c6 Qd1xg4 Nc6xd4 Bf1d3 h7h5 Qg4g5 Qb6c5 OO Qc5xg5 Bc1xg5
      7  00:00        12.291  819.000  +0.17  Be3c1 Nb8c6 Qd1xg4 Nc6xd4 Bf1d3 h7h5 Qg4g5 Qb6c5 OO Qc5xg5 Bc1xg5
      8  00:00        21.133  1.408.000  +0.17  Be3c1 Nb8c6 Qd1xg4 Nc6xd4 Bf1d3 h7h5 Qg4g5 Qb6c5 OO Qc5xg5 Bc1xg5
      8  00:00        29.910  1.994.000  +0.17  Be3c1 Nb8c6 Qd1xg4 Nc6xd4 Bf1d3 h7h5 Qg4g5 Qb6c5 OO Qc5xg5 Bc1xg5
      9-  00:00        55.255  1.782.000  +0.09  Be3c1 Nb8c6 Qd1xg4 Nc6xd4 Bf1d3 h7h5 Qg4g5 Qb6c5 OO Qc5xg5 Bc1xg5 Bf8d6 Nc3b5
      9  00:00        64.261  2.072.000  +0.19  Be3c1 Nb8c6 Qd1xg4 h7h5 Qg4g5 Nc6xd4 Bf1d3 Qb6c5 OO Qc5xg5 Bc1xg5 Bf8d6 Nc3b5
      9  00:00        64.306  2.074.000  +0.19  Be3c1 Nb8c6 Qd1xg4 h7h5 Qg4g5 Nc6xd4 Bf1d3 Qb6c5 OO Qc5xg5 Bc1xg5 Bf8d6 Nc3b5
     10  00:00        78.632  1.709.000  +0.19  Be3c1 Nb8c6 Qd1xg4 h7h5 Qg4g5 Nc6xd4 Bf1d3 Qb6c5 OO Qc5xg5 Bc1xg5 Bf8d6 Nc3b5
     10  00:00        94.197  2.047.000  +0.19  Be3c1 Nb8c6 Qd1xg4 h7h5 Qg4g5 Nc6xd4 Bf1d3 Qb6c5 OO Qc5xg5 Bc1xg5 Bf8d6 Nc3b5
     11+  00:00       172.685  2.213.000  +0.27  Be3c1 Nb8c6 Qd1xg4 h7h5 Qg4g5 Nc6xd4 Bf1d3 Qb6c5 OO Qc5xg5 Bc1xg5 Bf8d6 Nc3b5 Nd4xb5 Bd3xb5 Bd6e5
     11  00:00       180.847  2.318.000  +0.18  Be3c1 Nb8c6 Qd1xg4 h7h5 Qg4g5 Nc6xd4 Bf1d3 h5h4 h2h3 Qb6c5 OO Qc5xg5 Bc1xg5 a7a6 e4e5 d7d5 Bg5e3
     11  00:00       220.131  2.367.000  +0.18  Be3c1 Nb8c6 Qd1xg4 h7h5 Qg4g5 Nc6xd4 Bf1d3 h5h4 h2h3 Qb6c5 OO Qc5xg5 Bc1xg5 a7a6 e4e5 d7d5 Bg5e3
     12  00:00       331.585  2.674.000  +0.13  Be3c1 Bf8c5 Nc3a4 Qb6a5+ c2c3 Bc5xd4 Qd1xd4 OO b2b3 Nb8c6 Qd4c5 Qa5xc5 Na4xc5 b7b6 Nc5d3 Bc8a6 c3c4 Ba6b7 Bf1e2
     12  00:00       382.302  2.730.000  +0.13  Be3c1 Bf8c5 Nc3a4 Qb6a5+ c2c3 Bc5xd4 Qd1xd4 OO b2b3 Nb8c6 Qd4c5 Qa5xc5 Na4xc5 b7b6 Nc5d3 Bc8a6 c3c4 Ba6b7 Bf1e2
     13  00:00       583.102  2.886.000  +0.16  Be3c1 Bf8c5 Nc3a4 Qb6a5+ c2c3 Bc5xd4 Qd1xd4 Ng4f6 Qd4c4 Nb8c6 Na4c5 d7d6 b2b4 Qa5b6 Nc5a4 Qb6c7 Bf1e2 b7b5 Qc4xb5 Nf6xe4
     13  00:00       713.703  3.050.000  +0.16  Be3c1 Bf8c5 Nc3a4 Qb6a5+ c2c3 Bc5xd4 Qd1xd4 Ng4f6 Qd4c4 Nb8c6 Na4c5 d7d6 b2b4 Qa5b6 Nc5a4 Qb6c7 Bf1e2 b7b5 Qc4xb5 Nf6xe4
     14-  00:00     1.201.111  3.355.000  +0.08  Be3c1 Bf8c5 Nc3a4 Qb6a5+ c2c3 Bc5xd4 Qd1xd4 Ng4f6 Qd4c4 Nb8c6 Bc1f4 d7d5 e4xd5 Nf6xd5 Bf4d6 Qa5d8 Qc4c5 Qd8h4
     14+  00:01     1.843.935  3.587.000  +0.24  Qd1xg4 Qb6xb2 Ra1d1 Qb2xc3+ Rd1d2 Qc3a1+ Rd2d1 Qa1xa2
     14+  00:01     5.758.540  4.342.000  +1.81  Qd1xg4 Qb6xb2 Ra1d1 Qb2xc3+ Rd1d2 Qc3a1+ Rd2d1 Qa1xa2
     14  00:02     8.441.256  4.509.000  +1.79  Qd1xg4 Qb6xb2 Ke1d2 Qb2xa1 Nd4xe6 Qa1xc3+ Kd2xc3 d7xe6 Kc3b2 Bc8d7 Bf1e2 Bd7c6 Rh1d1 Nb8d7 Be3d4 Nd7f6 Bd4xf6 g7xf6 Qg4f4 Bf8e7 Qf4h6 Ra8d8 Qh6g7
     14  00:02     8.441.336  4.509.000  +1.79  Qd1xg4 Qb6xb2 Ke1d2 Qb2xa1 Nd4xe6 Qa1xc3+ Kd2xc3 d7xe6 Kc3b2 Bc8d7 Bf1e2 Bd7c6 Rh1d1 Nb8d7 Be3d4 Nd7f6 Bd4xf6 g7xf6 Qg4f4 Bf8e7 Qf4h6 Ra8d8 Qh6g7
     15+  00:02    10.208.054  4.608.000  +1.87  Qd1xg4 Qb6xb2 Ke1d2 Qb2xa1 Nd4xe6 Qa1xc3+ Kd2xc3 d7xe6 Kc3b2 Bc8d7 Bf1e2 Bd7c6 Rh1d1 Nb8d7 Be3d4 Nd7f6 Bd4xf6 g7xf6 Qg4f4 Bf8e7 Qf4h6 Ra8d8 Qh6g7
     15  00:02    10.609.498  4.626.000  +1.79  Qd1xg4 Qb6xb2 Ke1d2 Qb2xa1 Nd4xe6 Qa1xc3+ Kd2xc3 d7xe6 Kc3b2 Bc8d7 Bf1e2 Bd7c6 Rh1d1 Nb8d7 Be3d4 Nd7f6 Bd4xf6 g7xf6 Qg4f4 Bf8e7 Qf4h6 Ra8d8 Qh6g7
     15  00:02    10.653.237  4.584.000  +1.79  Qd1xg4 Qb6xb2 Ke1d2 Qb2xa1 Nd4xe6 Qa1xc3+ Kd2xc3 d7xe6 Kc3b2 Bc8d7 Bf1e2 Bd7c6 Rh1d1 Nb8d7 Be3d4 Nd7f6 Bd4xf6 g7xf6 Qg4f4 Bf8e7 Qf4h6 Ra8d8 Qh6g7
     16+  00:03    12.617.538  4.676.000  +1.87  Qd1xg4 Qb6xb2 Ke1d2 Qb2xa1 Nd4xe6 Qa1xc3+ Kd2xc3 d7xe6 Kc3b2 Bc8d7 Bf1e2 Bd7c6 Rh1d1 Nb8d7 Be3d4 Nd7f6 Bd4xf6 g7xf6 Qg4f4 Bf8e7 Qf4h6 Ra8d8 Qh6g7
     16  00:03    14.282.173  4.744.000  +1.77  Qd1xg4 Qb6xb2 Ke1d2 Qb2xa1 Nd4xe6 Qa1xc3+ Kd2xc3 d7xe6 Kc3b2 Bc8d7 Bf1e2 Bd7c6 Rh1d1 Nb8d7 f2f3 a7a6 Be3g1 Ra8d8 Bg1d4 Nd7f6 Qg4f4 Bf8e7 c2c3
     16  00:03    14.368.138  4.723.000  +1.77  Qd1xg4 Qb6xb2 Ke1d2 Qb2xa1 Nd4xe6 Qa1xc3+ Kd2xc3 d7xe6 Kc3b2 Bc8d7 Bf1e2 Bd7c6 Rh1d1 Nb8d7 f2f3 a7a6 Be3g1 Ra8d8 Bg1d4 Nd7f6 Qg4f4 Bf8e7 c2c3
     17+  00:04    20.335.269  4.864.000  +1.85  Qd1xg4 Qb6xb2 Ke1d2 Qb2xa1 Nd4xe6 Qa1xc3+ Kd2xc3 d7xe6 Kc3b2 Bc8d7 Bf1e2 Bd7c6 Rh1d1 Nb8d7 f2f3 a7a6 Be3d4 Ra8c8 Be2d3 Nd7f6 Qg4g5 h7h6 Qg5a5 Nf6d7 g2g4
     17  00:05    23.886.061  4.907.000  +1.88  Qd1xg4 Qb6xb2 Ke1d2 Qb2xa1 Nd4xe6 Qa1xc3+ Kd2xc3 d7xe6 Kc3b2 Bc8d7 Bf1c4 Nb8c6 Bc4b3 Ra8c8 Rh1d1 b7b6 Be3f4 g7g6 Qg4g3 Bf8g7+ c2c3 Nc6b4 e4e5 Nb4d5 Bb3xd5 e6xd5 Rd1xd5
     17  00:05    24.024.922  4.889.000  +1.88  Qd1xg4 Qb6xb2 Ke1d2 Qb2xa1 Nd4xe6 Qa1xc3+ Kd2xc3 d7xe6 Kc3b2 Bc8d7 Bf1c4 Nb8c6 Bc4b3 Ra8c8 Rh1d1 b7b6 Be3f4 g7g6 Qg4g3 Bf8g7+ c2c3 Nc6b4 e4e5 Nb4d5 Bb3xd5 e6xd5 Rd1xd5
     18  00:07    32.954.102  4.970.000  +1.84  Qd1xg4 Qb6xb2 Ke1d2 Qb2xa1 Nd4xe6 Qa1xc3+ Kd2xc3 d7xe6 Kc3b2 Bc8d7 f2f4 Nb8c6 Bf1e2 e6e5 f4f5 OOO Rh1d1 Kc8b8 Be2b5 Bd7c8 Bb5xc6 Rd8xd1 Qg4xd1 b7xc6 Qd1h5 f7f6 Qh5f7
     18  00:07    33.237.508  4.954.000  +1.84  Qd1xg4 Qb6xb2 Ke1d2 Qb2xa1 Nd4xe6 Qa1xc3+ Kd2xc3 d7xe6 Kc3b2 Bc8d7 f2f4 Nb8c6 Bf1e2 e6e5 f4f5 OOO Rh1d1 Kc8b8 Be2b5 Bd7c8 Bb5xc6 Rd8xd1 Qg4xd1 b7xc6 Qd1h5 f7f6 Qh5f7
     19  00:10    52.156.504  5.035.000  +1.84  Qd1xg4 Qb6xb2 Ke1d2 Qb2xa1 Nd4xe6 Qa1xc3+ Kd2xc3 d7xe6 Kc3b2 Bc8d7 Bf1c4 Nb8c6 Bc4b3 Ra8c8 Rh1d1 a7a6 Qg4h5 g7g6 Qh5h4 Bf8g7+ Kb2b1 b7b5 Be3c5 Rc8d8 f2f3 f7f6 f3f4 Bd7c8
     19  00:11    53.846.680  5.024.000  +1.84  Qd1xg4 Qb6xb2 Ke1d2 Qb2xa1 Nd4xe6 Qa1xc3+ Kd2xc3 d7xe6 Kc3b2 Bc8d7 Bf1c4 Nb8c6 Bc4b3 Ra8c8 Rh1d1 a7a6 Qg4h5 g7g6 Qh5h4 Bf8g7+ Kb2b1 b7b5 Be3c5 Rc8d8 f2f3 f7f6 f3f4 Bd7c8
     20+  00:17    87.566.425  5.066.000  +1.92  Qd1xg4 Qb6xb2 Ke1d2 Qb2xa1 Nd4xe6 Qa1xc3+ Kd2xc3 d7xe6 Kc3b2 Bc8d7 Bf1c4 Nb8c6 Bc4b3 Ra8c8 Rh1d1 a7a6 Qg4h5 g7g6 Qh5h4 Bf8g7+ Kb2b1 b7b5 Be3c5 Rc8d8 f2f3 f7f6 f3f4 Bd7c8
     20  00:21   107.723.786  5.111.000  +1.85  Qd1xg4 Qb6xb2 Ke1d2 Qb2xa1 Nd4xe6 Qa1xc3+ Kd2xc3 d7xe6 Bf1e2 Nb8c6 Kc3b2 g7g6 Rh1d1 Bf8g7+ c2c3 OO Qg4h4 b7b6 Be2b5 Nc6a5 Be3h6 Bg7xh6 Qh4xh6 Bc8b7 Qh6h4 Bb7c6 Bb5xc6 Na5xc6 Rd1d7 Nc6e5
     20  00:21   108.594.606  5.096.000  +1.85  Qd1xg4 Qb6xb2 Ke1d2 Qb2xa1 Nd4xe6 Qa1xc3+ Kd2xc3 d7xe6 Bf1e2 Nb8c6 Kc3b2 g7g6 Rh1d1 Bf8g7+ c2c3 OO Qg4h4 b7b6 Be2b5 Nc6a5 Be3h6 Bg7xh6 Qh4xh6 Bc8b7 Qh6h4 Bb7c6 Bb5xc6 Na5xc6 Rd1d7 Nc6e5
     21+  00:38   195.836.500  5.185.000  +1.93  Qd1xg4 Qb6xb2 Ke1d2 Qb2xa1 Nd4xe6 Qa1xc3+ Kd2xc3 d7xe6 Bf1e2 Nb8c6 Kc3b2 g7g6 c2c3 Bf8e7 Qg4g3 OO h2h4 Bc8d7 h4h5 Ra8d8 e4e5 Bd7c8 Be3h6 Rf8e8 Qg3f4 a7a6 h5xg6 h7xg6 Bh6g5 Be7xg5 Qf4xg5
     21  00:46   241.242.275  5.205.000  +1.95  Qd1xg4 Qb6xb2 Ke1d2 Qb2xa1 Nd4xe6 Qa1xc3+ Kd2xc3 d7xe6 Kc3b2 Bc8d7 Bf1c4 Nb8c6 Qg4g3 g7g6 Rh1d1 Bf8g7+ c2c3 Ra8c8 Bc4b3 Nc6b8 Be3d4 Bg7xd4 c3xd4 Nb8a6 Qg3d6 h7h6 h2h4 Na6c7 Rd1c1 Nc7b5
     21  00:47   243.255.384  5.192.000  +1.95  Qd1xg4 Qb6xb2 Ke1d2 Qb2xa1 Nd4xe6 Qa1xc3+ Kd2xc3 d7xe6 Kc3b2 Bc8d7 Bf1c4 Nb8c6 Qg4g3 g7g6 Rh1d1 Bf8g7+ c2c3 Ra8c8 Bc4b3 Nc6b8 Be3d4 Bg7xd4 c3xd4 Nb8a6 Qg3d6 h7h6 h2h4 Na6c7 Rd1c1 Nc7b5
     22  01:32   477.114.690  5.170.000  +2.00  Qd1xg4 Qb6xb2 Ke1d2 Qb2xa1 Nd4xe6 Qa1xc3+ Kd2xc3 d7xe6 Kc3b2 Bc8d7 Bf1c4 Nb8c6 Qg4g3 OOO Rh1d1 h7h5 h2h4 Bd7e8 Rd1xd8+ Kc8xd8 Bc4b5 g7g6 c2c3 Bf8g7 Bb5xc6 Be8xc6 Qg3f4 Kd8e8 Be3xa7 e6e5 Qf4e3
     22  01:33   480.377.493  5.157.000  +2.00  Qd1xg4 Qb6xb2 Ke1d2 Qb2xa1 Nd4xe6 Qa1xc3+ Kd2xc3 d7xe6 Kc3b2 Bc8d7 Bf1c4 Nb8c6 Qg4g3 OOO Rh1d1 h7h5 h2h4 Bd7e8 Rd1xd8+ Kc8xd8 Bc4b5 g7g6 c2c3 Bf8g7 Bb5xc6 Be8xc6 Qg3f4 Kd8e8 Be3xa7 e6e5 Qf4e3
     23  02:04   642.214.602  5.194.000  +1.99  Qd1xg4 Qb6xb2 Ke1d2 Qb2xa1 Nd4xe6 Qa1xc3+ Kd2xc3 d7xe6 Kc3b2 Bc8d7 Bf1c4 Nb8c6 Qg4g3 OOO Rh1d1 h7h5 h2h4 f7f6 f2f3 e6e5 Bc4d5 b7b6 f3f4 Rd8e8 f4f5 Kc8b8 c2c3 Re8c8 Bd5e6 Bd7xe6 f5xe6 Rc8e8
     23  02:05   648.036.839  5.188.000  +1.99  Qd1xg4 Qb6xb2 Ke1d2 Qb2xa1 Nd4xe6 Qa1xc3+ Kd2xc3 d7xe6 Kc3b2 Bc8d7 Bf1c4 Nb8c6 Qg4g3 OOO Rh1d1 h7h5 h2h4 f7f6 f2f3 e6e5 Bc4d5 b7b6 f3f4 Rd8e8 f4f5 Kc8b8 c2c3 Re8c8 Bd5e6 Bd7xe6 f5xe6 Rc8e8
   7/21/2010 12:39:58 PM, Time for this analysis: 00:03:00, Rated time: 00:01

1 of 1 matching moves
7/21/2010 12:39:59 PM, Total time: 12:29:30 AM
Rated time: 00:01 = 1 Seconds


Results for a bunch of engines:

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Analysis from Q:\qxg4.epd  
Analyzing engine: Stockfish-18-64-ja
7/21/2010 12:10:28 PM Level: 180 Seconds
  1) Qd1xg4             Qd1xg4  * 32 Seconds
1 of 1 matching moves
7/21/2010 12:13:34 PM, Total time: 12:03:05 AM Rated time: 00:32 = 32 Seconds

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Analysis from Q:\qxg4.epd  
Analyzing engine: Bright-0.5c
7/21/2010 12:10:28 PM Level: Blitz 1/1
  1) Qd1xg4             Qd1xg4  * 11 Seconds
1 of 1 matching moves
7/21/2010 12:16:43 PM, Total time: 12:06:14 AM Rated time: 00:11 = 11 Seconds

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Analysis from Q:\qxg4.epd  
Analyzing engine: Deep Rybka 4 x64
7/21/2010 12:10:28 PM Level: Blitz 1/1
  1) Qd1xg4             Qd1xg4  * 2 Seconds
1 of 1 matching moves
7/21/2010 12:20:16 PM, Total time: 12:09:47 AM Rated time: 00:02 = 2 Seconds

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Analysis from Q:\qxg4.epd  
Analyzing engine: Deepjunior2010.x64
7/21/2010 12:10:28 PM Level: Blitz 1/1
  1) Qd1xg4             Qd1xg4  * 36 Seconds
1 of 1 matching moves
7/21/2010 12:23:25 PM, Total time: 12:12:56 AM Rated time: 00:36 = 36 Seconds

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Analysis from Q:\qxg4.epd  
Analyzing engine: DeepShredder11UCI
7/21/2010 12:10:28 PM Level: Blitz 1/1
  1) Qd1xg4             Be3-c1  
0 of 1 matching moves
7/21/2010 12:26:54 PM, Total time: 12:16:25 AM Rated time: 03:00 = 180 Seconds

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Analysis from Q:\qxg4.epd  
Analyzing engine: DeepSjengWC2008_x64
7/21/2010 12:10:28 PM Level: Blitz 1/1
  1) Qd1xg4             Qd1xg4  * 168 Seconds
1 of 1 matching moves
7/21/2010 12:30:11 PM, Total time: 12:19:42 AM Rated time: 02:48 = 168 Seconds

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Analysis from Q:\qxg4.epd  
Analyzing engine: Fire_131_x64_KLO
7/21/2010 12:10:28 PM Level: Blitz 1/1
  1) Qd1xg4             Qd1xg4  * 4 Seconds
1 of 1 matching moves
7/21/2010 12:33:42 PM, Total time: 12:23:13 AM Rated time: 00:04 = 4 Seconds

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Analysis from Q:\qxg4.epd  
Analyzing engine: Houdini_x64_4CPU
7/21/2010 12:10:28 PM Level: Blitz 1/1
  1) Qd1xg4             Qd1xg4  * 1 Second
1 of 1 matching moves
7/21/2010 12:36:49 PM, Total time: 12:26:20 AM Rated time: 00:01 = 1 Seconds

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Analysis from Q:\qxg4.epd  
Analyzing engine: IvanHoe55Mod-x64
7/21/2010 12:10:28 PM Level: Blitz 1/1
  1) Qd1xg4             Qd1xg4  * 1 Second
1 of 1 matching moves
7/21/2010 12:39:59 PM, Total time: 12:29:30 AM Rated time: 00:01 = 1 Seconds

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Analysis from Q:\qxg4.epd  
Analyzing engine: Naum-4:64-bit
7/21/2010 12:10:28 PM Level: Blitz 1/1
  1) Qd1xg4             Nc3-a4  
0 of 1 matching moves
7/21/2010 12:43:11 PM, Total time: 12:32:42 AM Rated time: 03:00 = 180 Seconds

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Analysis from Q:\qxg4.epd  
Analyzing engine: Protector-133-64-ja
7/21/2010 12:10:28 PM Level: Blitz 1/1
  1) Qd1xg4             Qd1xg4  * 58 Seconds
1 of 1 matching moves
7/21/2010 12:46:29 PM, Total time: 12:36:00 AM Rated time: 00:58 = 58 Seconds

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Analysis from Q:\qxg4.epd  
Analyzing engine: Zappa_mexico_x64
7/21/2010 12:10:28 PM Level: Blitz 1/1
  1) Qd1xg4             Qd1xg4  * 68 Seconds
1 of 1 matching moves
7/21/2010 12:49:44 PM, Total time: 12:39:15 AM Rated time: 01:08 = 68 Seconds
Parent - By dcorbit (***) [us] Date 2010-07-21 20:14
Naum was set up wrong (multi-pv mode) and actually did solve it.  Arena gets confused in multi pv mode
Analysis from Q:\qxg4.epd  
7/21/2010 12:10:28 PM Level: Blitz 1/1
Analyzing engine: Naum-4:64-bit

1) Qxg4;               
    Searching move: Qd1xg4
    Best move (Naum-4:64-bit): Nc3-a4
    Not found in: 03:00
     5/15  00:00        18.399  836.318   0.00  Nc3a4 Qb6a5+ Na4c3 Qa5b6
     5/15  00:00        16.804  884.421  +0.11  Ra1b1 Ng4xe3 f2xe3 Nb8c6 Ke1f2
     5/15  00:00        15.607  918.058  +0.11  b2b3 Ng4xe3 f2xe3 Nb8c6 Ke1f2
     5/15  00:00        22.205  822.407  +0.47  Qd1d2 Ng4xe3 Qd2xe3 Qb6xb2 Ra1b1
   ---------------------------------------------------------------------------
     6/17  00:00        34.694  598.172   0.00  Nc3a4 Qb6a5+ Na4c3 Qa5b6
     6/17  00:00        33.076  648.549  +0.01  b2b3 Ng4xe3 f2xe3 Nb8c6 Ke1f2 Nc6xd4
     6/17  00:00        35.994  580.548  +0.10  Qd1d3 Ng4xe3 Qd3xe3 Qb6xb2
     6/17  00:00        31.374  653.625  +0.10  Qd1d2 Ng4xe3 Qd2xe3 Qb6xb2 Ra1b1 Qb2a3
   ---------------------------------------------------------------------------
     7/17  00:00        51.055  646.265  +0.03  Nc3a4 Qb6a5+ c2c3 Ng4xe3 f2xe3 Nb8c6 Ke1f2
     7/17  00:00        52.726  635.253  +0.09  Ra1b1 Ng4xe3 f2xe3 Nb8c6 Ke1f2 Nc6xd4 e3xd4
     7/16  00:00        43.978  619.408  +0.19  Qd1d3 Nb8c6 OOO Nc6xd4 Qd3xd4 Ng4xe3 f2xe3
     7/15  00:00        39.659  591.925  +0.24  Qd1d2 Ng4xe3 Qd2xe3 Qb6xb2 Ra1b1 Qb2a3 Rb1b3
   ---------------------------------------------------------------------------
     8/20  00:00        87.316  839.576  -0.01  Ra1b1 Ng4xe3 f2xe3 Nb8c6 Ke1f2 Nc6xd4 e3xd4 Bf8e7
     8/20  00:00        83.837  846.838  +0.09  Qd1d3 Nb8c6 OOO Ng4xe3 Qd3xe3 Nc6xd4 Qe3xd4 Qb6xd4
     8/20  00:00        94.393  865.990  +0.11  Nc3a4 Qb6a5+ c2c3 Ng4xe3 f2xe3 Nb8c6 Bf1e2 Bf8e7
     8/15  00:00        58.964  662.516  +0.18  Qd1d2 Ng4xe3 Qd2xe3 Qb6xb2 Ra1b1 Qb2a3 Rb1b3 Qa3a5
   ---------------------------------------------------------------------------
     9/23  00:00       144.807  1.056.985   0.00  Nc3a4 Qb6a5+ Na4c3 Qa5b6
     9/29  00:00       564.204  2.044.217  +0.05  Ra1b1 Ng4xe3 f2xe3 Nb8c6 Bf1b5 Nc6xd4 Qd1xd4 f7f6 Qd4xb6
     9/23  00:00       161.906  1.108.945  +0.15  Qd1d3 Ng4xe3 Qd3xe3 Qb6xb2
     9/18  00:00       115.105  920.840  +0.15  Qd1d2 Ng4xe3 Qd2xe3 Qb6xb2 Ra1b1 Qb2a3 Rb1b3 Qa3e7 Bf1e2
   ---------------------------------------------------------------------------
    10/29  00:00     1.008.133  2.458.860  +0.03  Qd1d3 Ng4xe3 f2xe3 Nb8c6 Bf1e2 Bf8c5 OOO Nc6e5 Qd3d2 OO
    10/29  00:00     1.029.537  2.445.456  +0.05  Ra1b1 Ng4xe3 f2xe3 Nb8c6 Bf1b5
    10/29  00:00       918.614  2.404.748  +0.05  Qd1d2 Ng4xe3 f2xe3 Qb6xb2 Ra1b1 Qb2a3 Bf1e2 Nb8c6 OO Nc6xd4
    10/29  00:00     1.367.106  2.526.998  +0.16  a2a3 Ng4xe3 f2xe3 Nb8c6 Bf1b5 Bf8e7 OO OO Rf1f4 Nc6xd4
   ---------------------------------------------------------------------------
    11/31  00:01     2.047.753  2.733.982   0.00  Qd1d2 Ng4xe3 f2xe3 Qb6xb2 Ra1b1 Qb2a3 Bf1e2 Bf8c5 e4e5 OO OO
    11/34  00:01     2.622.135  2.853.248  +0.04  Qd1d3 Ng4xe3 f2xe3 Nb8c6 Bf1e2 Qb6xb2 Ra1b1 Qb2a3 Nd4xc6 b7xc6 OO
    11/34  00:01     2.745.800  2.860.208  +0.09  Nc3a4 Qb6a5+ Be3d2 Qa5xa4 Bd2c3 Bf8c5 Bf1b5 Ng4xf2 Bb5xa4 Nf2xd1 Ra1xd1
    11/27  00:01     1.477.868  2.556.865  +0.10  a2a3 Ng4xe3 f2xe3 Nb8c6 Bf1b5 Bf8e7 OO OO Rf1f3 f7f5 e4xf5
   ---------------------------------------------------------------------------
    12/36  00:02     4.796.614  3.037.754   0.00  Ra1b1 Ng4xe3 f2xe3 Nb8c6 Bf1b5 Bf8e7 Nc3a4 Qb6a5+ Na4c3 Qa5b6
    12/36  00:02     4.398.988  3.017.138   0.00  Qd1d2 Ng4xe3 f2xe3 Qb6xb2 Ra1b1 Qb2a3 Bf1e2 Bf8c5
    12/26  00:02     3.288.093  2.904.675  +0.06  a2a3 Ng4xe3 f2xe3 Nb8c6 Bf1b5 Bf8e7 OO OO Nc3a4 Qb6c7 Bb5xc6 b7xc6
    12/36  00:02     7.369.015  3.216.505  +0.24  Be3c1 Nb8c6 Qd1xg4 Nc6xd4 Bf1d3 h7h5 Qg4g5 h5h4 h2h3 g7g6 OO Rh8h5
   ---------------------------------------------------------------------------
    13/34  00:03     9.861.767  3.302.668  -0.07  Qd1d2 Ng4xe3 f2xe3 Qb6xb2 Ra1b1 Qb2a3 Bf1e2 Qa3a5 Rb1b5 Qa5d8 OO Nb8c6 Be2h5
    13/34  00:03    10.542.964  3.320.618   0.00  Ra1b1 Ng4xe3 f2xe3 Nb8c6 Bf1b5 Bf8e7 Nc3a4 Qb6a5+ Na4c3 Qa5b6
    13/32  00:03     8.369.784  3.250.401  +0.05  a2a3 Ng4xe3 f2xe3 Nb8c6 Bf1b5 Bf8e7 Nc3a4 Qb6c7 OO OO Qd1d2
    13/29  00:03     7.831.380  3.226.773  +0.24  Be3c1 Nb8c6 Qd1xg4
   ---------------------------------------------------------------------------
    14/35  00:05    13.886.457  3.402.709  -0.01  a2a3 Ng4xe3 f2xe3 Nb8c6 Bf1b5 Bf8e7 OO Be7g5 Qd1d3 Bg5xe3+ Qd3xe3 Nc6xd4 Rf1f2 OO
    14/35  00:05    14.151.374  3.374.999   0.00  Ra1b1 Ng4xe3 f2xe3 Nb8c6 Bf1b5
    14/40  00:05    15.409.143  3.206.897  +0.05  Qd1d2 Ng4xe3 f2xe3 Qb6xb2 Ra1b1 Qb2a3 Bf1e2 Qa3a5 Nc3b5 Qa5xd2+ Ke1xd2 Nb8a6 e4e5 f7f6
    14/26  00:05    12.217.052  3.364.652  +0.16  Be3c1 Nb8c6 Qd1xg4 Nc6xd4 Bf1d3 h7h5 Qg4g5 h5h4 Qg5g4 h4h3 g2xh3 Bf8e7 OO Rh8h4
   ---------------------------------------------------------------------------
    15/53  00:22    77.188.423  3.514.155   0.00  Ra1b1 Ng4xe3 f2xe3 Nb8c6 Bf1b5 Bf8e7
    15/53  00:22    77.188.420  3.514.155  +0.05  Qd1d2 Ng4xe3 f2xe3 Qb6xb2 Ra1b1 Qb2a3 Bf1e2 Qa3a5 Nc3b5 Qa5xd2+ Ke1xd2
    15/53  00:22    77.188.417  3.514.155  +0.35  Be3c1 Nb8c6 Qd1xg4 Nc6xd4 Qg4d1 Nd4c6 Bf1e2 Bf8e7 OO OO Nc3b5 Nc6e5 Bc1f4 f7f6 Qd1d4
    15/53  00:22    77.188.414  3.514.154  +1.81  Qd1xg4
   ---------------------------------------------------------------------------
    16/47  00:35   103.832.454  3.598.795  -0.02  Qd1d2 Ng4xe3 f2xe3 Qb6xb2 Ra1b1 Qb2a3 Bf1e2 a7a6 OO Bf8b4 Rb1b3 Qa3a5 a2a3 Bb4e7 Rf1d1 Qa5c7
    16/49  00:35   128.747.994  3.626.193  +0.06  Nc3a4 Qb6a5+ Be3d2 Qa5xa4 Bd2c3 Ng4xf2 Ke1xf2 Bf8b4 Qd1d2 Bb4xc3 Qd2xc3 Nb8c6 Ra1d1 Nc6xd4 Rd1xd4 Qa4c6
    16/47  00:35   100.629.231  3.589.670  +0.35  Be3c1 Nb8c6 Qd1xg4
    16/47  00:35   100.629.228  3.589.670  +1.83  Qd1xg4 Qb6xb2 Ke1d2 Qb2xa1 Nd4xe6 Qa1xc3+ Kd2xc3 d7xe6 Qg4g3 a7a6 Bf1e2 Nb8c6 Rh1d1 g7g6 Kc3b3 e6e5
   ---------------------------------------------------------------------------
    17/61  01:37   364.456.239  3.759.645   0.00  Nc3d5 e6xd5 Qd1xg4 Qb6xb2 Ra1c1 Bf8b4+ Ke1d1 OO Nd4f5 d7d6 Nf5h6+ Kg8h8 Nh6xf7+ Kh8g8 Nf7h6+ Kg8h8 Nh6f7+
    17/57  01:37   216.334.887  3.730.169   0.00  Nc3a4 Qb6a5+ Be3d2 Qa5xa4 Bd2c3 Ng4xf2 Ke1xf2 a7a6 a2a3 Bf8c5 Kf2g3 d7d5 Bf1d3 Bc5d6+ Kg3h4 Qa4d7 e4xd5
    17/46  01:37   158.990.736  3.710.055  +0.23  Be3c1 Nb8c6 Qd1xg4 Nc6xd4 Qg4d1 Nd4c6 Bf1e2 Bf8e7 OO OO Nc3b5 Qb6c5 Bc1f4 Qc5b4 Bf4d6 Be7xd6 Nb5xd6
    17/46  01:37   157.597.690  3.703.736  +1.77  Qd1xg4 Qb6xb2 Ke1d2 Qb2xa1 Nd4xe6 Qa1xc3+ Kd2xc3 d7xe6 Qg4g3 a7a6 Bf1e2 Nb8c6 Rh1d1 g7g6 Kc3b2 Bf8g7+ c2c3
   ---------------------------------------------------------------------------
    18/46  02:06   461.690.243  3.816.505  -0.02  Nc3a4 Qb6a5+ Na4c3 Ng4xe3 f2xe3 Nb8c6 a2a3 Bf8e7 Bf1b5 Be7f6 Qd1d2 h7h6 Qd2f2 OO OO Bf6e5 Qf2d2 Qa5b6
    18/48  02:06   482.765.831  3.829.317   0.00  Nc3d5 e6xd5 Qd1xg4 Qb6xb2 Ra1c1 Bf8b4+ Ke1d1 OO Nd4f5
    18/46  02:06   424.962.009  3.823.629  +0.28  Be3c1 Nb8c6 Qd1xg4 Nc6xd4 Qg4d1 Nd4c6 Bf1e2 Bf8e7 OO OO Ra1b1 Nc6d4 Bc1e3 Nd4xe2+ Qd1xe2 Qb6a5 Qe2b5 Qa5xb5
    18/46  02:06   424.962.006  3.823.629  +1.94  Qd1xg4 Qb6xb2 Ke1d2 Qb2xa1 Nd4xe6 Qa1xc3+ Kd2xc3 d7xe6 Qg4g3 a7a6 Bf1e2 Nb8c6 Kc3b2 g7g6 c2c3 Bf8e7 Be3h6 Bc8d7
   ---------------------------------------------------------------------------
    18/46  02:38   461.690.243  3.816.505  +0.34  Nc3a4 Qb6a5+ Na4c3 Ng4xe3 f2xe3 Nb8c6 a2a3 Bf8e7 Bf1b5 Be7f6 Qd1d2 h7h6 Qd2f2 OO OO Bf6e5 Qf2d2 Qa5b6
    18/48  02:38   482.765.831  3.829.317  +0.34  Nc3d5 e6xd5 Qd1xg4 Qb6xb2 Ra1c1 Bf8b4+ Ke1d1 OO Nd4f5
    19/57  02:38   612.691.627  3.877.770  +0.28  Be3c1 Nb8c6 Qd1xg4 Nc6xd4 Qg4d1 Nd4c6 Bf1e2 Bf8e7 OO
    19/57  02:38   595.071.608  3.871.114  +1.88  Qd1xg4 Qb6xb2 Ke1d2 Qb2xa1 Nd4xe6 Qa1xc3+ Kd2xc3 d7xe6 Qg4g3 a7a6 Bf1e2 Nb8c6 Kc3b2 g7g6 c2c3 Bf8e7 Be3h6 Bc8d7 Rh1d1
   7/21/2010 12:43:10 PM, Time for this analysis: 00:03:00, Rated time: 03:00

0 of 1 matching moves
7/21/2010 12:43:11 PM, Total time: 12:32:42 AM
Rated time: 03:00 = 180 Seconds
- - By Bonuskent (*) Date 2010-07-22 23:45
I’m no big fan of monster logs, but nice work anyway!

What about the ban to talk about certain engines at this site? Is it accepted now? But ok — these Rybka babies are fast just like their mother.

Not all the tests were made with properly cleaned hashtables, it seems. But that’s not so important right now. We can conclude that there’s a huge time span between different strong engines to solve this and I wonder why.

It’s a question about search, not about evaluation. If I’m right the engine must search 15 plies in 7.Qxg4 to make a clear plus obvious. Some engines do that fifty or hundred times faster than others and I wonder why? It’s not because Rybka (and her babies) count moves hundred times faster. Interesting variations must have priority to get searched deeper, otherwise this can’t be solved so fast. Is Rybka helped to keep the interest in 7.Qxg4 alive because 9.Ndb5 looks ok, or would she be equally fast (or faster) if all alternatives after 7.Qxg4 were really bad for white? Or does she when the black queen is on a1, just like a human, find the possibility of Bf1 to somewhere so cool so it must be investigated?

Personally I’m interested in how a chess engines search works, not in code but in words. I find the development the latest years fascinating. Can someone explain or suggest somewhere to read more about it.
Parent - - By dcorbit (***) [us] Date 2010-07-23 21:58
The latest big developments in computer chess are all about search.
If you examine the new, strong chess engines you will see something in common with all of them:
A branching factor of about 2.
Branching factor means: Going from one ply {half-move} to the next, how much longer does it take?
If you look at the average position in a chess game, it seems that the mathematical branching factor is about 36.  That means that for a given position, there are usually about 36 move choices.  So, it stands to reason that each new ply would take 36 times as long as the previous ply, if we spent the same effort on each node.  In fact, that is how it works with pure mini-max search.http://en.wikipedia.org/wiki/Minimax
However, there was -- quite some time ago -- a development called alpha-beta search.  This allowed for much faster searching.  The idea works like this:
If I search the bag I think is best first, and my guess is pretty good, I can save some time.  Suppose in the first bag I search, I see that the worst thing the opponent can do to me is capture a pawn.  If I examine the second bag and see that he can take a knight, I do not have to continue searching that bag, it is already worst than the first bag.  And so it goes with all the other bags (34 more on average).  Here is a better explanation:
http://en.wikipedia.org/wiki/Alpha-beta_pruning
Alpha beta reduces the branching factor from 36 to 6, approximately (square root of 36)
There are some other clever things we can do to reduce the branching factor.   One example is null move pruning, which is based on the observation that if a position is so good that I could say "I pass" we can save some work:
http://en.wikipedia.org/wiki/Null-move_heuristic
Null move reduces the branching factor to about 4.
There are other things we can do to spend less effort searching useless nodes.  One of the modern developments is called "late move reductions" as popularized by Fruit:
http://www.glaurungchess.com/lmr.html

The biggest difficulty in chess is that the game is exponential.  So anything we can do to lower the size of the exponent will have a huge payoff, provided that we are eliminating work in the right places.

Consider pure mini-max chess.  We will consider the opening position which begins with a branch factor of 20.  This site shows how quickly the nodes explode:
http://www.albert.nu/programs/dperft/main.htm
By ply 11 we are already at 2,097,651,003,696,806 nodes.  If our chess engine can search at 200 M NPS (Deeper Blue search speed) it will take 10488255 seconds to reach 11 plies using pure minimax = 2913 hours = 121 days.
Pure alpha-beta would reduce this to 45,800,120 nodes which would resolve in about 1/5 of a second.  We get similar mind-numbing reductions for null move and LMR.

The strongest chess engines all share the low branching factor as the major reason for their strength.
Parent - - By Bonuskent (*) Date 2010-07-26 17:03
Thank you, dcorbit! You gave me some good thinking. “Your” search is something like this:

First we start with the idea of a full search for every move. Then we speed it up by removing garbage from the search. Completely safe for alpha-beta pruning and only very slightly risky for null-move heuristic. I’d like to call that “negative programming”. Then we notice that the winners from our searches seldom are late bloomers and therefore we introduce late move reductions to spend less time for the underdog moves and more time for the favorites.

And that’s it? Are there also techniques for “positive programming”? I mean nodes that are so cool or important or special in some way so they must be searched deeper than standard?
Parent - By dcorbit (***) [us] Date 2010-07-26 19:53
Nodes that are searched deeper than the standard search are called extensions.
There are many types of extensions.  One of them is called single reply extensions.  We should always do that one because it is free.  In other words, if we have only one choice (the move is forced and without alternatives) then we should simply go past it and search the next node.
Check extensions are another common extension.  We see a special sort of danger in that we are forcing responses (or being forced) and there may be a checkmate or stalemate imminent.
Recapture extensions are practically a necessity.  If (for instance) someone captures my knight, I had better have a good response or I am probably going to lose.  So if I can recapture an equivalent to the loss, I make the recapture move and extend one ply in the search.
Checkmate threats discovered via null move search and pawn races are other common extensions.

There is a danger in extensions in that if they are not used carefully, they can explode the search.  Reductions are much safer in this regard.

Here is a nice place to find out more about it:
http://chessprogramming.wikispaces.com/Extensions
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