Author: Anthony Cozzie
Date: 14:07:37 08/10/04
Go up one level in this thread
On August 09, 2004 at 16:02:38, Anthony Cozzie wrote: >On August 09, 2004 at 14:25:30, Stuart Cracraft wrote: > >>[D]r1bqkb1r/2pp1ppp/p1n2p2/1p2p3/4P3/1B3N2/PPPP1PPP/RNBQ1RK1 b q - 4 1 >> >>I don't know if I filled in the castle flags right but in this position >>black still has both rights left. >> >>The question is, if your program values bishops more than knights, >>how do you prevent it from playing Na5 to capture the White Bishop >>but then giving up the pawn at e5 (since the capture Nxe4 by black >>is unplayable). (e.g. 1. ... Na5 2. Nxe5 Nxb3 3. ab) >> >>I've searched this to 10 full ply with unlimited quiescence >>and it still can't see that Na5 is bad. >> >>It would help if some people posted their searches and mention >>how they avoid this kind of issue. >> >>My search: >> >>Alpha=-255 Beta=245 Maxdepth=99 MaxTime=9999999 >> 1/11> c6a5 0.00 245 68 c6a5 >> 1/11 f6e4 0.01 1026 159 f6e4 >> 2/15 f6e4 0.01 1008 946 f6e4 f1e1 >> 3/17< f6e4 0.02 758 4181 f6e4 d2d4 e5d4 >> 3/20 f6e4 0.04 75 7143 f6e4 b3d5 e4f6 >> 4/30 f6e4 0.13 75 24970 f6e4 b3d5 e4f6 d5c6 >> 5/34 c6a5 0.50 57 104715 c6a5 f1e1 a5b3 a2b3 c8b7 >> 6/34 c6a5 1.22 45 256985 c6a5 f1e1 a5b3 a2b3 c8b7 b1c3 >> 7/42 c6a5 4.31 32 889215 c6a5 f3e5 a5b3 c2b3 f8d6 d2d4 f6e4 >> 8/51 c6a5 24.86 19 5021946 c6a5 f3e5 a5b3 c2b3 d8e7 d2d4 d7d6 e5f3 >> 9/54 c6a5 115.27 19 19483875 c6a5 f3e5 a5b3 c2b3 d8e7 d2d4 d7d6 e5f3 >>10/54 c6a5 264.28 26 44999682 c6a5 f1e1 a5b3 a2b3 c8b7 d2d4 f6e4 b1d2 d7d5 >> >> >>Stuart > >Why don't you play Na5 Nxe5 and see what your engine thinks? > >anthony 1... Nf6xe4 2. Rf1-e1 d7-d5 3. Nb1-c3 Bf8-c5 4. Nc3xe4 d5xe4 5. Re1xe4 = (0.14) Depth: 7/22 00:00:00.69 129kN (187 KN/s, 37 splits, 8 aborts) 1... Nc6-a5 2. Nb1-c3 Na5xb3 3. a2xb3 Bc8-b7 4. d2-d4 d7-d5 5. e4xd5 e5xd4 = (0.24) Depth: 7/22 00:00:01.15 264kN (229 KN/s, 54 splits, 11 aborts) 1... Nc6-a5 2. Nb1-c3 Na5xb3 3. a2xb3 Bc8-b7 4. d2-d4 d7-d5 5. e4xd5 e5xd4 = (0.24) Depth: 7/22 00:00:01.29 313kN (243 KN/s, 71 splits, 16 aborts) 1... Nc6-a5 2. Rf1-e1 Na5xb3 3. a2xb3 Bc8-b7 4. d2-d3 Bf8-b4 5. Nb1-c3 = (0.23) Depth: 8/24 00:00:01.58 435kN (274 KN/s, 81 splits, 17 aborts) 1... Nc6-a5 2. Rf1-e1 Na5xb3 3. a2xb3 Bc8-b7 4. d2-d3 Bf8-b4 5. Nb1-c3 = (0.23) Depth: 8/24 00:00:02.14 764kN (356 KN/s, 130 splits, 22 aborts) 1... Nc6-a5 2. Nf3xe5 Na5xb3 3. c2xb3 Bf8-d6 4. d2-d4 Nf6xe4 5. Qd1-f3 Bd6xe5 6. d4xe5 = (0.07) Depth: 9/24 00:00:02.52 1033kN (410 KN/s, 141 splits, 23 aborts) 1... Nc6-a5 2. Nf3xe5 Na5xb3 3. c2xb3 Bf8-d6 4. d2-d4 Nf6xe4 5. Qd1-f3 Bd6xe5 6. d4xe5 = (0.07) Depth: 9/24 00:00:05.29 3667kN (692 KN/s, 230 splits, 49 aborts) 1... Nc6-a5 2. d2-d3 Na5xb3 3. a2xb3 Qd8-e7 4. Nb1-c3 b5-b4 5. Nc3-e2 d7-d5 6. Bc1-g5 = (0.09) Depth: 10/24 00:00:05.85 4408kN (753 KN/s, 251 splits, 51 aborts) 1... Nc6-a5 2. d2-d3 Na5xb3 3. a2xb3 Qd8-e7 4. Nb1-c3 b5-b4 5. Nc3-e2 d7-d5 6. Bc1-g5 = (0.09) Depth: 10/27 00:00:07.75 6794kN (876 KN/s, 375 splits, 59 aborts) 1... Nc6-a5 2. Nf3xe5 Na5xb3 3. c2xb3 Qd8-e7 4. d2-d4 Nf6xe4 5. Qd1-c2 Bc8-b7 6. Qc2xc7 Bb7-d5 = (-0.04) Depth: 11/27 00:00:08.86 8273kN (933 KN/s, 391 splits, 62 aborts) 1... Nf6xe4 2. Rf1-e1 d7-d5 3. Nb1-c3 Ne4xc3 4. d2xc3 Bc8-e6 5. Nf3xe5 Nc6xe5 6. Re1xe5 Bf8-d6 = (0.15) Depth: 11/27 00:00:10.56 10629kN (1006 KN/s, 419 splits, 69 aborts) 1... Nf6xe4 2. Rf1-e1 d7-d5 3. Nb1-c3 Ne4xc3 4. d2xc3 Bc8-e6 5. Nf3xe5 Nc6xe5 6. Re1xe5 Bf8-d6 = (0.15) Depth: 11/29 00:00:12.59 13345kN (1060 KN/s, 532 splits, 72 aborts) 1... Nf6xe4 2. Rf1-e1 d7-d5 3. Nb1-c3 Ne4xc3 4. d2xc3 Bc8-e6 5. Nf3xe5 Nc6-a5 6. Bc1-e3 Bf8-e7 7. Be3-f4 Na5xb3 8. a2xb3 = (0.04) Depth: 12/29 00:00:15.54 17177kN (1105 KN/s, 544 splits, 73 aborts) 1... Nf6xe4 2. Rf1-e1 d7-d5 3. Nb1-c3 Ne4xc3 4. d2xc3 Bc8-e6 5. Nf3xe5 Nc6-a5 6. Bc1-e3 Bf8-e7 7. Be3-f4 = (0.04) Depth: 12/30 00:00:36.21 43489kN (1201 KN/s, 741 splits, 94 aborts) 1... Nf6xe4 2. Rf1-e1 d7-d5 3. d2-d3 Ne4-f6 4. Nf3xe5 Nc6xe5 5. Re1xe5 Bc8-e6 6. Nb1-c3 Bf8-d6 7. Re5-g5 d5-d4 8. Bb3xe6 f7xe6 = (-0.08) Depth: 13/35 00:00:42.64 52272kN (1226 KN/s, 773 splits, 96 aborts) 1... Bf8-e7 2. Nb1-c3 d7-d6 3. a2-a4 b5-b4 4. Nc3-d5 Nf6xe4 5. Nd5xe7 Nc6xe7 6. d2-d4 Bc8-g4 7. d4xe5 d6xe5 8. Qd1xd8 Ra8xd8 9. Nf3xe5 = (-0.04) Depth: 13/35 00:01:19.55 99149kN (1246 KN/s, 838 splits, 110 aborts) 1... Bf8-e7 2. Nb1-c3 d7-d6 3. a2-a4 b5-b4 4. Nc3-d5 Nf6xe4 5. Nd5xe7 Nc6xe7 6. d2-d4 Bc8-g4 7. d4xe5 d6xe5 8. Qd1xd8 = (-0.04) Depth: 13/37 00:02:19.21 170583kN (1225 KN/s, 1040 splits, 124 aborts) Zappa also needs 10 ply to drop Na5, and it finally gets the book move Be7 at 13 ply and about a minute. I think its just tactics to realize that black loses e5 pawn and can't pick up the e4 pawn because of various pins. anthony
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