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Subject: A theoretical novelty found by ExChess

Author: Dann Corbit

Date: 22:39:41 01/15/02


In this post:
http://www.icdchess.com/forums/1/message.shtml?207574

Benny Antonsson proposed this position:
[D]r1bqk1nr/pppp1p1p/2n3p1/1B6/1b1NP3/2P5/PP3PPP/RNBQK2R b KQkq - 0 1

Which has the well known response Bg7 (played almost 100% since the 1800's).

ExChess analysis said this:
ExChess takes 55 seconds, and switches to something novel, Qe7:

Starting search on position:
r1bqkbnr/pppp1p1p/2n3p1/1B6/3NP3/8/PPP2PPP/RNBQK2R b KQkq -
Target search time: 99900
Starting depth: 1
Game stage: 0
  1.  -0.45     0    88750   1. ... Nf6
  2.  -0.60     0    88837   1. ... Nf6 2. Nc3
  3.  -0.66     0    89105   1. ... Nf6 2. Nxc6 dxc6 3. Qxd8+ Kxd8 4. Bd3
  3.  -0.62     0    89439   1. ... Nxd4 2. Qxd4 Nf6 3. O-O
  4.  -0.55     0    90147   1. ... Nxd4 2. Qxd4 Nf6 3. Nc3
  4.  -0.53     0    92019   1. ... Nf6 2. Nxc6 dxc6 3. Qxd8+ Kxd8 4. Bg5 Bb4+
5. c3 cxb5 6. cxb4
  5.  -0.60     0    94733   1. ... Nf6 2. Nxc6 bxc6 3. Bd3 d5 4. Nc3
  6.  -0.48     0   120149   1. ... Nf6 2. Nxc6 bxc6 3. Bd3 d5 4. Nc3 Bb4
  6.  -0.38     0   166730   1. ... Bb4+ 2. c3 Bd6 3. O-O Qh4 4. f4 Nf6
  7.  -0.49     0   282419   1. ... Bb4+ 2. c3 Bd6 3. Qc2 Nxd4 4. cxd4 Qh4 5. g3
Qd8
  7.  -0.34     2   722552   1. ... Qh4 2. Qd3 Nf6 3. Nc3 Bc5 4. Be3 O-O
  8.   --
  8.  -0.66     3  1298018   1. ... Qh4 2. O-O Nxd4 3. Qxd4 Bd6 4. g3 Qf6 5. Be3
  8.  -0.63     4  1452288   1. ... Nxd4 2. Qxd4 Nf6 3. Nc3 Be7 4. Nd5 O-O 5.
Nxe7+ Qxe7 6. Bd3
  8.   ++       5  1815142   1. ... Nf6
  8.  -0.53     5  1988130   1. ... Nf6 2. Nxc6 bxc6 3. Bd3 d5 4. Nc3 Bg4 5. Be2
Qd7
  9.  -0.44    11  3681706   1. ... Nf6 2. Nxc6 bxc6 3. Bd3 d5 4. Nc3 Bg7 5. O-O
O-O 6. Bg5
 10.  -0.47    25  8482210   1. ... Nf6 2. Nc3 Bb4 3. Bg5 Bxc3+ 4. bxc3 Ne5 5.
O-O a6 6. Ba4 O-O
 10.  -0.43    43 15062239   1. ... Nge7 2. Nxc6 Nxc6 3. O-O Bg7 4. Nd2 O-O 5.
Nf3 Qe8 6. Re1 d6
 10.  -0.36    55 19389717   1. ... Bg7 2. Nf3 Nf6 3. Nc3 O-O 4. O-O d6 5. Bg5
Bg4 6. Re1
 11.  -0.41    74 26236534   1. ... Bg7 2. Nxc6 bxc6 3. Bd3 Ne7 4. O-O O-O 5.
Nc3
 12.  -0.34   151 53365883   1. ... Bg7 2. Nxc6 bxc6 3. Be2 Ne7 4. O-O O-O 5.
Nd2 d5 6. Re1 Rb8 7. Rb1 Bb7
 13.  -0.37   283 99583026   1. ... Bg7 2. Nxc6 bxc6 3. Be2 Ne7 4. O-O O-O 5.
Nc3 d5 6. Bg5 Bxc3 7. bxc3 Re8 8. Bd3
 13.  -0.36   707 244330518   1. ... Qe7 2. Nc3 Bg7 3. Nde2 Nf6 4. Bg5 Qc5 5.
Be3 Qh5 6. Nf4 Qxd1+ 7. Rxd1 Nb4 8. Rd2 O-O


So I analyzed the position after Qe7 and after Bg7 using Yace:
[D]r1b1k1nr/ppppqpbp/2n3p1/1B6/3NP3/8/PPP2PPP/RNBQK2R w KQkq -
[D]r1bqk1nr/pppp1pbp/2n3p1/1B6/3NP3/8/PPP2PPP/RNBQK2R w KQkq -

white ( 1): input: hash 300M
hash size wanted 300000000
Stored 8 learned positions into hash table
entries 24999999 size 299999988 size_wanted 300000000 tts3 8333332
white ( 1): input: post
white ( 1): input: st 300
white ( 1): input: epd \bg7-qe7.epd
r1bqk1nr/pppp1pbp/2n3p1/1B6/3NP3/8/PPP2PPP/RNBQK2R w KQkq -
Stored 8 learned positions into hash table
solution
no solutions
usetime = 299.00, mintime = 299.00 maxtime = 299.00 tl 299.00 ml 0
         8   0.000   0.15  1t  1.Bxc6 dxc6 {-10}
        21   0.001   0.36  1t  1.Nxc6 dxc6 2.Qxd8+ Kxd8 {0}
        79   0.001   0.42  1t  1.Be3 {0}
       110   0.002   0.42  1.  1.Be3 {0}
       250   0.002   0.17  2t  1.Be3 Nge7 {0}
       283   0.003   0.36  2t+ 1.Nxc6 dxc6 2.Qxd8+H Kxd8H {0}
       312   0.003   0.36  2t  1.Nxc6 dxc6 2.Qxd8+H Kxd8H {0}
       778   0.005   0.36  2.  1.Nxc6 dxc6 2.Qxd8+ Kxd8 {0}
      1883   0.008   0.21  3t  1.Nxc6 bxc6 2.Be2 d5 {0}
      2257   0.010   0.26  3t+ 1.Be3 Qh4 2.Nxc6 dxc6 {0}
      3602   0.015   0.44  3t  1.Be3 a6 2.Nxc6 {340}
      4686   0.018   0.44  3.  1.Be3 a6 2.Nxc6 {340}
      7705   0.030   0.21  4t  1.Be3 Nge7 2.O-O O-O {0}
     15136   0.049   0.21  4.  1.Be3 Nge7 2.O-O O-O {0}
     30885   0.106   0.43  5t  1.Be3 Nge7 2.O-O O-O 3.Nc3 {0}
     53896   0.157   0.43  5.  1.Be3 Nge7 2.O-O O-O 3.Nc3 {0}
     93946   0.282   0.24  6t  1.Be3 a6 2.Bc4 Qf6 3.Nxc6 Qxc6 {0}
    105286   0.317   0.25  6t+ 1.Nxc6 dxc6 2.Qxd8+ Kxd8 3.Be2 Bxb2 4.Bxb2 Ne7
                               {270}
    156003   0.455   0.27  6t  1.Nxc6 bxc6 2.Be2 Rb8 3.c3 d5 4.Nd2 {0}
    200876   0.564   0.27  6.  1.Nxc6 bxc6 2.Be2 Rb8 3.c3 d5 4.Nd2 {0}
    363113   1.083   0.19  7t  1.Nxc6 bxc6 2.Bd3 Ne7 3.O-O O-O 4.Nc3 d5H {0}
    505215   1.523   0.20  7t+ 1.Be3 a6 2.Be2 Nxd4 3.Bxd4 Nf6
    571153   1.891   0.25  7t  1.Be3 a6 2.Be2 d5 3.exd5 Qxd5 4.Bf3 Qa5+ 5.Nc3
                               {0}
    813042   2.459   0.25  7.  1.Be3 a6 2.Be2 d5 3.exd5 Qxd5 4.Bf3 Qa5+ 5.Nc3
                               {0}
   2151136   6.273   0.32  8t  1.Be3 Qf6 2.Bxc6 bxc6 3.Nc3H Qg5H 4.Bxg5H Bxd4H
                               {651}
   2288864   6.603   0.33  8t+ 1.Nxc6 bxc6 2.Bd3 Ne7 3.O-O O-O 4.Nc3 d5 5.Be3
                               {0}
   2548902   7.278   0.42  8t  1.Nxc6 bxc6 2.Bd3 Ne7 3.O-O O-O 4.Nc3 Rb8 5.Qg4
                               Bxc3 6.bxc3 {10}
   2970013   8.276   0.42  8.  1.Nxc6 bxc6 2.Bd3 Ne7 3.O-O O-O 4.Nc3 Rb8 5.Qg4
                               Bxc3 6.bxc3 {10}
   3887949  10.819   0.26  9t  1.Nxc6 bxc6 2.Be2 Qh4 3.Qd3 Ne7 4.Nc3 O-O 5.O-O
                               Be5 {0}
   6299812  17.054   0.26  9.  1.Nxc6 bxc6 2.Be2 Qh4 3.Qd3 Ne7 4.Nc3 O-O 5.O-O
                               Be5 {0}
   8590292  23.075   0.30 10t  1.Nxc6 bxc6 2.Be2 Qh4 3.Nd2 Ne7 4.g3 Qh3 5.Bf1
                               Qe6 6.Bc4H {0}
  14215011  38.579   0.30 10.  1.Nxc6 bxc6 2.Be2 Qh4 3.Nd2 Ne7 4.g3 Qh3 5.Bf1
                               Qe6 6.Bc4 {0}
  19909410  54.519   0.25 11t  1.Nxc6 bxc6 2.Be2 Ne7 3.O-O O-O 4.Nc3H Bxc3H
                               5.bxc3H Rb8H 6.Bg5H f6H 7.Be3H d5H {10}
  36198436  1:38.5   0.25 11.  1.Nxc6 bxc6 2.Be2 Ne7 3.O-O O-O 4.Nc3 Bxc3
                               5.bxc3 Rb8 6.Bg5 f6 7.Be3 d5 {10}
  58950721  2:44.0   0.29 12t  1.Nxc6 bxc6 2.Be2 Qh4 3.O-O Ne7 4.Qd3H Qxh2+H
                               5.Kxh2H Be5+H 6.g3H Ba6H {921}
 100470548  4:44.1   0.29 12.  1.Nxc6 bxc6 2.Be2 Qh4 3.O-O Ne7 4.Qd3 Qxh2+
                               5.Kxh2 Be5+ 6.g3 Ba6 {921}
 105257186  4:58.9   0.29 12f. 1.Nxc6 bxc6 2.Be2 Qh4 3.O-O Ne7 4.Qd3 Qxh2+
                               5.Kxh2 Be5+ 6.g3 Ba6 {921}
105257186 Nodes, 33.14% Leavenodes, 352040 Nodes/sec
76179067 eval, 40.59% score, 335514218 genmoves, 17.55% captures le 295/287
ext: pawn 9501, rcp 557838, chk 1389272, repchk 197487, null 2808, prune 7450610
htable: 80322930 store, 0 rejected, 103346753 probe, 30.5% f/p, 39.2% f/s
entries 24999999 age 0 renew 0
egtb probes 0, found 0 max_depth 34
r1b1k1nr/ppppqpbp/2n3p1/1B6/3NP3/8/PPP2PPP/RNBQK2R w KQkq -
Stored 8 learned positions into hash table
solution
no solutions
usetime = 299.00, mintime = 299.00 maxtime = 299.00 tl 299.00 ml 0
        12   0.001   0.11  1t  1.Bxc6 dxc6 {-10}
       230   0.003   0.11  1.  1.Bxc6 dxc6 {-10}
       279   0.003   0.11  2t  1.Bxc6 dxc6 {-10}
       488   0.004   0.11  2.  1.Bxc6 dxc6 {-10}
      1701   0.009   0.09  3t  1.Bxc6 bxc6 2.Nc3 Ba6 {-10}
      3707   0.013   0.09  3.  1.Bxc6 bxc6 2.Nc3 Ba6 {-10}
     11875   0.039   0.14  4t  1.Bxc6 dxc6 2.f3 Qb4+ 3.c3 Qc4H {-10}
     15461   0.049   0.14  4.  1.Bxc6 dxc6 2.f3 Qb4+ 3.c3 Qc4 {-10}
     27793   0.086  -0.08  5t  1.Bxc6 dxc6 2.f3 Qd6 3.c3 Ne7 {-10}
     48714   0.135  -0.08  5.  1.Bxc6 dxc6 2.f3 Qd6 3.c3 Ne7 {-10}
    134901   0.386   0.21  6t  1.Bxc6 dxc6 2.O-O Nf6 3.Bg5 Qe5 4.Bxf6 {330}
    161510   0.446   0.21  6.  1.Bxc6 dxc6 2.O-O Nf6 3.Bg5 Qe5 4.Bxf6 {330}
    263940   0.761   0.13  7t  1.Bxc6 dxc6 2.O-O Bd7 3.Nc3 O-O-O 4.Bf4 Kb8
                               {-10}
    412585   1.066   0.13  7.  1.Bxc6 dxc6 2.O-O Bd7 3.Nc3 O-O-O 4.Bf4 Kb8
                               {-10}
    797557   2.081   0.18  8t  1.Bxc6 dxc6 2.O-O Nf6 3.Nc3 c5 4.Nb3 O-O 5.Bg5
                               {-10}
   1110358   2.841   0.18  8.  1.Bxc6 dxc6 2.O-O Nf6 3.Nc3 c5 4.Nb3 O-O 5.Bg5
                               {-10}
   1999130   5.386  -0.01  9t  1.Bxc6 dxc6 2.O-O Nf6 3.Bg5 O-O 4.Nc3 Qc5
                               5.Bxf6 Bxf6 {-20}
   4319081  11.820  -0.01  9.  1.Bxc6 dxc6 2.O-O Nf6 3.Bg5 O-O 4.Nc3 Qc5
                               5.Bxf6 Bxf6 {-20}
   8695091  24.357  -0.10 10t  1.Bxc6 dxc6 2.O-O Bd7 3.Nf3 O-O-O 4.Qe2 Nf6
                               5.Nc3 Kb8 6.Bf4 {-10}
  14048464  39.023  -0.10 10.  1.Bxc6 dxc6 2.O-O Bd7 3.Nf3 O-O-O 4.Qe2 Nf6
                               5.Nc3 Kb8 6.Bf4 {-10}
  22448475  1:04.0  -0.25 11t  1.Bxc6 dxc6 2.O-O Bd7 3.Nc3 O-O-O 4.Be3 c5
                               5.Nb3 Bxc3 6.bxc3 Qxe4 {-80}
  38849992  1:48.3  -0.25 11.  1.Bxc6 dxc6 2.O-O Bd7 3.Nc3 O-O-O 4.Be3 c5
                               5.Nb3 Bxc3 6.bxc3 Qxe4 {-80}
  69386394  3:17.4  -0.16 12t  1.Bxc6 dxc6 2.O-O Bd7 3.Nf3 O-O-O 4.Qe2 Nf6
                               5.Nc3 Rhe8 6.Bg5 h6 7.Bh4 {-10}
 104332826  4:58.9  -0.16 12u. 1.Bxc6 dxc6 2.O-O Bd7 3.Nf3 O-O-O 4.Qe2 Nf6
                               5.Nc3 Rhe8 6.Bg5 h6 7.Bh4 {-10}
104332826 Nodes, 31.97% Leavenodes, 348951 Nodes/sec
76587351 eval, 38.04% score, 378443434 genmoves, 14.50% captures le 276/318
ext: pawn 2313, rcp 480244, chk 2012822, repchk 369075, null 4601, prune 6543116
htable: 82461187 store, 0 rejected, 102262991 probe, 26.9% f/p, 33.4% f/s
entries 24999999 age 0 renew 0
egtb probes 0, found 0 max_depth 40
0 nodes, 0 leavenodes in 619.52 sec 0 n/s
test nodes 0 win nodes 0 mate nodes 0
win time 0.00 mate time 0.00 av depth 0.000 (nm 0.000) maxdepth 40, tu 915
log(win_nodes) = 0.00000 log(win_time) = 0.00000
white ( 1): input: quit

How about that!



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