Just for fun I wanted to see if White was already lost at move 16.
Material not decisive but deceiving. It is not a difficult position, not for Stockfish and others I mean; even Mephisto Schach III UCI will do, they will show very quickly a good score but takes awhile to really get big for the ensuing endgame at least with Stockfish dev and Rebel EAS I tried before that. Sometimes earlier on Stock does not get very high depths, like eight minutes for a depth under 30 and Multi PV = 3. But I saw no real search explosions.
White at the moment here at move 26 in this sideline, Knight ahead, black bishop hanging and after Qg5 threatening mate in one Qxg7+ in Black's castle. But it means nothing. Black does a pseudo queen sac and will win the endgame. Not difficult for the computer but very complex for me I think, if I had it on the board even as correspondence chess not able to use a computer. With the computer it is just relaxing, waiting for the iterations Sort of a meditation.
This was the diagram of the position, it follows from a line in Ajedracista's game if White did not outright blunder at move 16 but plays 16. Bxc4. Still down but computer sees about minus 1.11 for White (Rebel EAS 3.0 in this case, when at move 16, see game)
[d]1r2r1k1/5ppp/p4P2/2Q5/b1pP3P/2N2q1N/P1PK4/2R4R w - -
Engine: Stockfish dev-20260726-23cf5d82 (1024 MB)
gemaakt door the Stockfish developers (see AUTHORS f
28 10:18 -4.33 26.Dg5 Dd3+ 27.cxd3 Tb2+ 28.Tc2 Txc2+
29.Kd1 Txc3+ 30.Kd2 Tc2+ 31.Kd1 Tg2+
32.Kc1 Txg5 33.Pxg5 cxd3 34.Pf3 gxf6
35.Te1 Td8 36.Te3 Lb5 37.Kd2 Kf8
38.a4 Lxa4 39.Ph2 (342.168.569) 553
28 10:18 -4.41 26.Tce1 Dg2+ 27.Te2 Txe2+ 28.Pxe2 Te8
29.Phg1 c3+ 30.Dxc3 Dxh1 31.Dg3 g6
32.Pc3 Lc6 33.Pge2 Df1 34.Pf4 Dc4
35.Df2 Td8 36.d5 Ld7 37.Pfe2 Tc8
38.Dd4 h5 39.De4 (342.168.569) 553
28 10:18 -8.95 26.De7 Txe7 27.fxe7 Dg2+ 28.Ke3 Te8
29.Pf2 Dg3+ 30.Ke2 Dxc3 31.Kf1 Txe7
32.Th2 Ld7 33.h5 h6 34.Tb1 Te8 35.a3 Kh7
36.a4 Lc6 37.Td1 De3 38.d5 Ld7
39.Tb1 (342.168.569) 553
_______________________________________________________________
29 25:26 -4.31 26.Dg5 Dd3+ 27.cxd3 Tb2+ 28.Tc2 Txc2+
29.Kd1 Txc3+ 30.Kd2 Tc2+ 31.Kd1 Tg2+
32.Kc1 Txg5 33.hxg5 Td8 34.dxc4 Txd4
35.c5 Td5 36.Tg1 Txc5+ 37.Kd2 Ld7
38.Pf4 h6 39.gxh6 (877.373.013) 574
29 25:26 -4.44 26.Tce1 Dg2+ 27.Te2 Txe2+ 28.Pxe2 Te8
29.Phg1 c3+ 30.Dxc3 Dxh1 31.Dg3 g6
32.Pc3 Lc6 33.Pge2 Df1 34.Pf4 Dc4
35.Df2 Td8 36.d5 Ld7 37.Pfe2 Tc8
38.Dd4 h5 39.De4 (877.373.013) 574
29 25:26 -9.12 26.De7 Txe7 27.fxe7 Dg2+ 28.Ke3 Te8
29.Pf2 Dg3+ 30.Ke2 Dxc3 31.Kf1 Txe7
32.Th2 Ld7 33.Tb1 h5 34.a4 Te8
35.Td1 Kh7 36.a5 Kh8 37.d5 De3
38.Tb1 c3 39.Tg2 (877.373.013) 574
(Game follows in other post below if you would like to see how I got here.)
Arabian mate not (sideline)
Moderator: Ras
-
Eelco de Groot
- Posts: 4743
- Joined: Sun Mar 12, 2006 2:40 am
- Full name: Eelco de Groot
Arabian mate not (sideline)
Last edited by Eelco de Groot on Thu Aug 13, 2026 1:59 pm, edited 1 time in total.
Debugging is twice as hard as writing the code in the first
place. Therefore, if you write the code as cleverly as possible, you
are, by definition, not smart enough to debug it.
-- Brian W. Kernighan
place. Therefore, if you write the code as cleverly as possible, you
are, by definition, not smart enough to debug it.
-- Brian W. Kernighan
-
Eelco de Groot
- Posts: 4743
- Joined: Sun Mar 12, 2006 2:40 am
- Full name: Eelco de Groot
Re: Arabian mate not (sideline)
[pgn]
[Event "?"]
[Site "?"]
[Date "2026.08.13"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]
1. d4 d5 2. Nf3 Nf6 3. Bf4 e6 4. Nc3 Bd6 5. Bxd6 Qxd6 6. e3
O-O 7. Bd3 c5 8. dxc5 Qxc5 9. Ng5 Nc6 10. h4 a6 11. Qe2 Bd7
12. O-O-O Rac8 13. g4 b5 14. f3 Na5 15. Nh3 Nc4 16. Rde1 $2
(16. Bxc4 {-1.11/12 149:49m Rebel EAS 3.0 This is a bit
better.} bxc4 17. Qd2 Rb8 (17... Rb8 {-1.95/42 179:25m more
Rebel EAS 3.0} 18. g5 Qb4 19. Qd4 Qxb2+ 20. Kd2 e5 21. Qxe5
Ba4 22. Rc1 d4 23. exd4 {This is Stockfish Dev's move at
this point, Nxa4 was from Rebel's PV.} (23. Nxa4 Qb4+
24. Ke2 d3+ 25. Kf1 Nh5 26. Kg2 Rfe8 27. Qc5 Qxa4 28. cxd3
Rb2+ 29. Nf2 cxd3 30. Qc4 Qxc4) 23... Rfe8 {-3.72/34 6:34m}
24. Qc5 Qb7 25. gxf6 Qxf3 {Position from diagram in first
post, analysis Stockfish.} 26. Qg5 Qd3+ 27. cxd3 Rb2+
28. Rc2 Rxc2+ 29. Kd1 Rxc3+ 30. Kd2 Rc2+ 31. Kd1 Rg2+
32. Kc1 Rxg5 33. hxg5 Rd8 34. dxc4 Rxd4 35. c5 Rd5 36. Rg1
Rxc5+) 18. Ne2 Rfc8 19. Qc3 Qb6 20. g5 Ne8 21. e4) 16... b4
17. Nb1 a5 18. g5 Ne8 19. h5 a4 20. g6 h6 21. gxf7+ Rxf7
22. Bg6 Rf6 23. Nf4 Nxe3 24. Nd3 Qxc2+ 25. Qxc2 Rxc2# *
[/pgn]
[Event "?"]
[Site "?"]
[Date "2026.08.13"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]
1. d4 d5 2. Nf3 Nf6 3. Bf4 e6 4. Nc3 Bd6 5. Bxd6 Qxd6 6. e3
O-O 7. Bd3 c5 8. dxc5 Qxc5 9. Ng5 Nc6 10. h4 a6 11. Qe2 Bd7
12. O-O-O Rac8 13. g4 b5 14. f3 Na5 15. Nh3 Nc4 16. Rde1 $2
(16. Bxc4 {-1.11/12 149:49m Rebel EAS 3.0 This is a bit
better.} bxc4 17. Qd2 Rb8 (17... Rb8 {-1.95/42 179:25m more
Rebel EAS 3.0} 18. g5 Qb4 19. Qd4 Qxb2+ 20. Kd2 e5 21. Qxe5
Ba4 22. Rc1 d4 23. exd4 {This is Stockfish Dev's move at
this point, Nxa4 was from Rebel's PV.} (23. Nxa4 Qb4+
24. Ke2 d3+ 25. Kf1 Nh5 26. Kg2 Rfe8 27. Qc5 Qxa4 28. cxd3
Rb2+ 29. Nf2 cxd3 30. Qc4 Qxc4) 23... Rfe8 {-3.72/34 6:34m}
24. Qc5 Qb7 25. gxf6 Qxf3 {Position from diagram in first
post, analysis Stockfish.} 26. Qg5 Qd3+ 27. cxd3 Rb2+
28. Rc2 Rxc2+ 29. Kd1 Rxc3+ 30. Kd2 Rc2+ 31. Kd1 Rg2+
32. Kc1 Rxg5 33. hxg5 Rd8 34. dxc4 Rxd4 35. c5 Rd5 36. Rg1
Rxc5+) 18. Ne2 Rfc8 19. Qc3 Qb6 20. g5 Ne8 21. e4) 16... b4
17. Nb1 a5 18. g5 Ne8 19. h5 a4 20. g6 h6 21. gxf7+ Rxf7
22. Bg6 Rf6 23. Nf4 Nxe3 24. Nd3 Qxc2+ 25. Qxc2 Rxc2# *
[/pgn]
Debugging is twice as hard as writing the code in the first
place. Therefore, if you write the code as cleverly as possible, you
are, by definition, not smart enough to debug it.
-- Brian W. Kernighan
place. Therefore, if you write the code as cleverly as possible, you
are, by definition, not smart enough to debug it.
-- Brian W. Kernighan
-
Eelco de Groot
- Posts: 4743
- Joined: Sun Mar 12, 2006 2:40 am
- Full name: Eelco de Groot
Re: Arabian mate not (sideline)
A small correction of/for the game record I gave for this line; the -1.11 after 11 plies deep at 149 minutes was not Rebel EAS 3.0 yet but completely on its own found by Mephisto III Schach set at its maximum depth of 64 plies. Notice also the strong 17.Qd2! that Rebel would only play one move later if it had been its choice and quite a lot more plies. So the beginning of this line is all from Mephisto III!
Checking the line after 17...Rb8 was indeed by Rebel EAS 3.0 and later Stockfish.
Mephisto III UCI output:
[d]2r2rk1/3b1ppp/p3pn2/1pqp4/2n3PP/2NBPP1N/PPP1Q3/2KR3R w - -
Engine: Schach III Maxdepth (1024 MB)
gemaakt door Original 68000 program by Thomas Nitsche [and Elmar Henne]
6/50 0:03 -0.83 16.Lxc4 bxc4 17.Th2 Tb8 18.Tf1 Lb5
19.e4 (80.865) 22
7/38 0:13 -0.92 16.Lxc4 bxc4 17.g5 Ph5 18.Tdg1 Db6
19.f4 g6 20.e4 (294.566) 22
8/48 1:12 -0.48 16.Lxc4 bxc4 17.h5 Tb8 18.h6 gxh6
19.Tdg1 Db6 (1.663.038) 22
9/45 6:22 -1.10 16.Lxc4 bxc4 17.Df2 Tb8 18.e4 Dd6
19.g5 Ph5 20.exd5 Db4 21.Da7 Dxb2+
22.Kd2 Db7 23.Dxb7 Txb7 (8.960.162) 23
10/41 18:54 -0.61 16.Lxc4 bxc4 17.Tdg1 Db6 18.Kb1 Db4
19.Pd1 e5 20.h5 Db5 21.g5 Pxh5 22.f4 Lxh3
23.Dxh5 Lf5 24.g6 Lxg6 25.Txg6 fxg6
26.Dxh7+ Kf7 27.fxe5 (25.466.470) 22
11/39 149:49 -1.11 16.Lxc4 bxc4 17.Dd2{!} Tb8 18.Pe2 Tfc8
19.Dc3 Db6 20.g5 Pe8 21.e4 (211.487.878) 23
Analysis from Rebel:
[d]2r2rk1/3b1ppp/p3pn2/1pqp4/2n3PP/2NBPP1N/PPP1Q3/2KR3R w - -
Checking the line after 17...Rb8 was indeed by Rebel EAS 3.0 and later Stockfish.
Mephisto III UCI output:
[d]2r2rk1/3b1ppp/p3pn2/1pqp4/2n3PP/2NBPP1N/PPP1Q3/2KR3R w - -
Engine: Schach III Maxdepth (1024 MB)
gemaakt door Original 68000 program by Thomas Nitsche [and Elmar Henne]
6/50 0:03 -0.83 16.Lxc4 bxc4 17.Th2 Tb8 18.Tf1 Lb5
19.e4 (80.865) 22
7/38 0:13 -0.92 16.Lxc4 bxc4 17.g5 Ph5 18.Tdg1 Db6
19.f4 g6 20.e4 (294.566) 22
8/48 1:12 -0.48 16.Lxc4 bxc4 17.h5 Tb8 18.h6 gxh6
19.Tdg1 Db6 (1.663.038) 22
9/45 6:22 -1.10 16.Lxc4 bxc4 17.Df2 Tb8 18.e4 Dd6
19.g5 Ph5 20.exd5 Db4 21.Da7 Dxb2+
22.Kd2 Db7 23.Dxb7 Txb7 (8.960.162) 23
10/41 18:54 -0.61 16.Lxc4 bxc4 17.Tdg1 Db6 18.Kb1 Db4
19.Pd1 e5 20.h5 Db5 21.g5 Pxh5 22.f4 Lxh3
23.Dxh5 Lf5 24.g6 Lxg6 25.Txg6 fxg6
26.Dxh7+ Kf7 27.fxe5 (25.466.470) 22
11/39 149:49 -1.11 16.Lxc4 bxc4 17.Dd2{!} Tb8 18.Pe2 Tfc8
19.Dc3 Db6 20.g5 Pe8 21.e4 (211.487.878) 23
Analysis from Rebel:
[d]2r2rk1/3b1ppp/p3pn2/1pqp4/2n3PP/2NBPP1N/PPP1Q3/2KR3R w - -
Code: Select all
Engine: Rebel EAS 3.0 (1024 MB)
gemaakt door Ed Schroder & Chris Whittington (C) 200
17/31 0:01 -1.51 16.Lxc4 bxc4 17.g5 Ph5 18.De1 Lc6
19.f4 Tb8 20.Td4 Tb6 21.Pf2 Pg3 (1.078.358) 668
18/32 0:02 -1.61++ 16.Lxc4 (1.380.914) 670
18/36 0:02 -1.38++ 16.Lxc4 (1.442.160) 672
18/36 0:02 -1.84 16.Lxc4 bxc4 17.Pf4 Tb8 18.g5 Pe8
19.h5 Txb2 20.Kxb2 Db4+ 21.Kc1 Dxc3
22.De1 Da3+ 23.Kd2 La4 24.Ke2 Lxc2
25.Tc1 Ld3+ 26.Kf2 Db2+ 27.Kg1 De5
28.Pxd3 Dxg5+ 29.Kf2 (1.557.257) 672
19/43 0:02 -1.74++ 16.Lxc4 (1.655.299) 673
19/29 0:02 -1.70 16.Lxc4 bxc4 17.Pf4 Tb8 18.g5 Pe8
19.h5 Txb2 20.Kxb2 Db4+ 21.Kc1 Dxc3
22.De1 Da3+ 23.Kd2 La4 24.Ke2 Lxc2
25.Tc1 Ld3+ 26.Kf2 Dxa2+ 27.Kg1 Pd6
28.Th2 Da3 (1.690.900) 674
20/41 0:02 -1.60++ 16.Lxc4 (1.788.111) 674
20/37 0:02 -1.50++ 16.Lxc4 (1.828.767) 676
20/40 0:02 -1.34++ 16.Lxc4 (1.943.174) 676
20/46 0:03 -1.12++ 16.Lxc4 (2.187.708) 676
20/48 0:06 -1.51 16.Lxc4 bxc4 17.Pf4 Lc6 18.g5 Pd7
19.g6 hxg6 20.Df2 Tb8 21.Pfe2 e5
22.h5 g5 23.Dg1 f6 24.f4 Db4 25.fxg5 Dxb2+
26.Kd2 (4.128.001) 663
21/44 0:07 -1.41++ 16.Lxc4 (4.926.858) 658
21/41 0:07 -1.31++ 16.Lxc4 (5.038.082) 659
21/46 0:07 -1.15++ 16.Lxc4 (5.137.246) 661
21/46 0:08 -0.93++ 16.Lxc4 (5.766.665) 658
21/40 0:13 -1.10++ 16.Lxc4 (8.671.511) 647
21/48 0:16 -1.66 16.Lxc4 bxc4 17.Pf4 Lc6 18.g5 Pd7
19.h5 Tb8 20.g6 Txb2 21.h6 fxg6
22.hxg7 Te8 23.Txh7 Kxh7 24.Dh2+ Kxg7
25.Dg1 Txc2+ 26.Kxc2 Pf8 27.Ph5+ Kf7
28.Dg5 gxh5 29.Tg1 (10.667.586) 645
22/51 0:19 -1.55++ 16.Lxc4 (12.397.505) 643
22/37 0:19 -1.45++ 16.Lxc4 (12.501.780) 643
22/35 0:19 -1.30++ 16.Lxc4 (12.591.759) 644
22/42 0:22 -1.07++ 16.Lxc4 (14.229.496) 646
22/46 0:26 -1.47 16.Lxc4 bxc4 17.Pf4 Lc6 18.Dd2 Tb8
19.Ph5 Pxh5 20.gxh5 Db4 21.Dd4 f6
22.Dg4 Tfe8 23.h6 Tb7 24.Tdg1 f5
25.Dg5 Dxb2+ 26.Kd2 Da3 27.Tb1 Td7
28.Thg1 d4 29.exd4 (17.037.143) 646
23/48 0:27 -1.47++ 16.Lxc4 (18.102.083) 646
23/37 0:28 -1.32++ 16.Lxc4 (18.228.152) 647
23/46 0:30 -1.42 16.Lxc4 bxc4 17.Pf4 Lc6 18.Dd2 Tb8
19.Ph5 Pxh5 20.gxh5 Db4 21.Dd4 f6
22.Dg4 Tfe8 23.h6 Tb7 24.Thg1 e5
25.h5 Dxb2+ 26.Kd2 Tf7 27.Tb1 Da3
28.Tb8 Dd6 29.Txe8+ (19.835.481) 647
24/47 0:31 -1.32++ 16.Lxc4 (20.368.239) 647
24/44 0:32 -1.22++ 16.Lxc4 (20.802.643) 648
24/48 0:33 -1.29++ 16.Lxc4 (22.031.548) 648
24/50 0:38 -1.35++ 16.Lxc4 (24.759.104) 648
24/36 0:38 -1.50 16.Lxc4 bxc4 17.Pf4 Lc6 18.Dd2 Tb8
19.Ph5 Pxh5 20.gxh5 Db4 21.Dd4 f6
22.Pe2 e5 23.Dc3 Dxc3 24.bxc3 h6
25.Pg3 d4 26.e4 dxc3 27.Pf5 La4
28.Thg1 Tb7 29.Td6 (24.840.901) 648
25/48 0:49 -1.60++ 16.Lxc4 (32.062.399) 649
25/36 0:49 -1.37++ 16.Lxc4 (32.386.578) 649
25/49 0:52 -1.72 16.Lxc4 bxc4 17.Pf4 Lc6 18.g5 Pd7
19.g6 hxg6 20.h5 g5 21.Pg6 Tfe8
22.Tdg1 d4 23.exd4 Dxd4 24.Td1 Df6
25.Pe4 Lxe4 26.fxe4 Pe5 27.Pxe5 Dxe5
28.h6 Ted8 29.Txd8+ (34.139.483) 649
26/50 1:05 -1.62++ 16.Lxc4 (42.739.938) 647
26/47 1:06 -1.52++ 16.Lxc4 (43.284.756) 648
26/44 1:08 -1.36++ 16.Lxc4 (44.244.871) 648
26/48 1:12 -1.14++ 16.Lxc4 (47.129.912) 648
26/51 1:59 -1.78 16.Lxc4 bxc4 17.Pf4 Lc6 18.g5 Pd7
19.Df2 Tb8 20.Pfe2 Db4 21.h5 e5
22.h6 g6 23.Kd2 f6 24.gxf6 Dc5
25.Thf1 Pxf6 26.f4 Txb2 27.fxe5 Pe4+
28.Pxe4 Da5+ 29.P4c3 (77.573.549) 648
27/44 2:02 -1.68++ 16.Lxc4 (79.609.899) 649
27/35 2:02 -1.69 16.Lxc4 bxc4 17.Pf4 Lc6 18.g5 Pd7
19.Df2 Tb8 20.Pfe2 Db4 21.h5 e5
22.h6 g6 23.Kd2 f6 24.gxf6 Dc5
25.Thf1 Pxf6 26.Dg1 Db6 27.b3 Db4
28.Kc1 cxb3 29.axb3 (79.643.080) 649
28/49 2:32 -1.69++ 16.Lxc4 (98.673.767) 646
28/51 2:36 -1.53++ 16.Lxc4 (101.235.327) 647
28/47 2:38 -1.31++ 16.Lxc4 (102.331.316) 647
28/47 2:43 -1.41 16.Lxc4 bxc4 17.Pf4 Lc6 18.Dd2 Tb8
19.Dd4 Dd6 20.Ph5 Pxh5 21.gxh5 e5
22.Dxc4 d4 23.Pe4 Lxe4 24.fxe4 Tfc8
25.Dd3 Db4 26.Db3 dxe3 27.Td7 Tf8
28.c4 Dxb3 29.axb3 (105.850.643) 647
29/51 3:40 -1.64++ 16.Lxc4 (142.730.897) 646
29/53 4:13 -1.65++ 16.Lxc4 (164.442.414) 648
29/54 4:17 -1.50 16.Lxc4 bxc4 17.Pf4 Lc6 18.Dd2 Tb8
19.Dd4 Dd6 20.Ph5 Pxh5 21.gxh5 e5
22.Dxc4 d4 23.Pe4 Lxe4 24.fxe4 Tfc8
25.Da4 d3 26.Td2 Db6 27.Db3 Txc2+
28.Txc2 Dxe3+ 29.Kb1 (166.741.807) 648
30/54 4:50 -1.50++ 16.Lxc4 (188.361.060) 647
30/58 5:01 -1.34++ 16.Lxc4 (195.501.522) 648
30/56 5:13 -1.34 16.Lxc4 bxc4 17.Pf4 Lc6 18.Dd2 Tb8
19.Dd4 Dd6 20.Ph5 Pe8 21.f4 f6
22.Thf1 Db4 23.g5 Pd6 24.gxf6 Dxb2+
25.Kd2 Dxc3+ 26.Kxc3 Pb5+ 27.Kd2 Pxd4
28.exd4 g6 29.f5 (203.583.591) 648
31/60 6:55 -1.57++ 16.Lxc4 (268.567.140) 646
31/48 7:22 -1.57++ 16.Lxc4 (286.606.210) 647
31/60 7:39 -1.31 16.Lxc4 bxc4 17.Pf4 Lc6 18.Dd2 Tb8
19.Dd4 Dd6 20.Ph5 Pxh5 21.gxh5 e5
22.Dxc4 d4 23.Pe4 Lxe4 24.fxe4 Tfc8
25.Da4 Tb4 26.Da3 Dc5 27.Th2 dxe3
28.Te2 Db6 29.h6 (298.074.860) 648
32/51 9:09 -1.53++ 16.Lxc4 (357.246.908) 649
32/54 9:19 -1.52 16.Lxc4 bxc4 17.Pf4 Lc6 18.Dd2 Tb8
19.Dd4 Dd6 20.Ph5 Pe8 21.f4 f6
22.Tdf1 Db4 23.g5 Dxb2+ 24.Kd2 Pd6
25.gxf6 Dxc3+ 26.Kxc3 Pb5+ 27.Kd2 c3+
28.Kd3 Pxd4 29.Kxd4 (364.062.745) 650
33/54 9:38 -1.42++ 16.Lxc4 (376.724.599) 651
33/56 9:44 -1.32++ 16.Lxc4 (380.567.016) 651
33/58 11:54 -1.62++ 16.Lxc4 (466.621.354) 653
33/51 11:59 -1.78 16.Lxc4 bxc4 17.Pf4 Lc6 18.Dd2 Tb8
19.Dd4 Dd6 20.Ph5 Pe8 21.f4 f6
22.Tdf1 Db4 23.g5 Dxb2+ 24.Kd2 Pd6
25.gxf6 Dxc3+ 26.Kxc3 Pb5+ 27.Kd2 Pxd4
28.exd4 g6 29.Pg3 (469.931.201) 653
34/57 12:05 -1.67++ 16.Lxc4 (473.898.355) 653
34/56 12:15 -1.57++ 16.Lxc4 (480.688.200) 653
34/55 12:29 -1.42++ 16.Lxc4 (490.280.317) 654
34/63 16:59 -1.66 16.Lxc4 bxc4 17.Pf4 Lc6 18.Dd2 Tb8
19.Dd4 Dd6 20.Ph5 Pe8 21.f4 f6
22.Tdf1 Db4 23.g5 Dxb2+ 24.Kd2 Pd6
25.gxf6 Dxc3+ 26.Kxc3 Pb5+ 27.Kd2 Pxd4
28.exd4 g6 29.Pg3 (669.588.634) 656 Debugging is twice as hard as writing the code in the first
place. Therefore, if you write the code as cleverly as possible, you
are, by definition, not smart enough to debug it.
-- Brian W. Kernighan
place. Therefore, if you write the code as cleverly as possible, you
are, by definition, not smart enough to debug it.
-- Brian W. Kernighan
-
Ajedrecista
- Posts: 2267
- Joined: Wed Jul 13, 2011 9:04 pm
- Location: Madrid, Spain.
Re: Arabian mate not (sideline).
Hello Eelco:
[d]1r2r1k1/5ppp/p4P2/6Q1/b1pP3P/2N2q1N/P1PK4/2R4R b - - 1 26
26.- ..., Qd3+! is hilarious. Then, R+B start a nice combo with R visiting b8-b2-c2-c3-c2-g2-g5. It is important to note 29.- ..., Rxc3+! to capture the white knight that was threatening the black bishop instead of rushing with 29.- ..., Rg2+?
Some old engines see the idea instantly, namely AnMon 5.60, Dragon 4.6, Hermann 2.4 64-bit, Nejmet 3.07, ProDeo 1.5, Ruffian 1.0.5 and SOS 5.1 for Arena; with ProDeo 1.5 returning a drawish evaluation of circa -0.28 and the rest of engines evaluating black more generously.
------------
I also want to note that if you miss 26.- ..., Qd3+! and play 26.- ..., g6 instead, I expected a checkmate by white with Qh6 and Qg7#, completely forgetting that white lacks of king safety and would be mated after 27.- Qh6??, Qg2+:
[pgn][Event ""]
[Site ""]
[Round ""]
[Date "2026.08.15"]
[SetUp "1"]
[FEN "1r2r1k1/5p1p/p4Pp1/6Q1/b1pP3P/2N2q1N/P1PK4/2R4R w - - 0 27"]
[Result "*"]
27.Rb1 (27.Rf1 (27.Qh6?? Qg2+ 28.Nf2 (28.Ne2 (28.Kd1 Qg4+ 29.Kd2 (29.Ne2 Qxe2# 0-1) Qxd4# 0-1) 0-1) 28...Qxf2+ 0-1) *) *[/pgn]
When only Rb1 and Rf1 are reasonable for white.
Regards from Spain.
Ajedrecista.
Fantasy position! Glad that my thread inspired you:Eelco de Groot wrote: ↑Thu Aug 13, 2026 1:34 pm[...]
[...] it follows from a line in Ajedracista's game if White did not outright blunder at move 16 but plays 16. Bxc4. [...]
[...]
[d]1r2r1k1/5ppp/p4P2/6Q1/b1pP3P/2N2q1N/P1PK4/2R4R b - - 1 26
26.- ..., Qd3+! is hilarious. Then, R+B start a nice combo with R visiting b8-b2-c2-c3-c2-g2-g5. It is important to note 29.- ..., Rxc3+! to capture the white knight that was threatening the black bishop instead of rushing with 29.- ..., Rg2+?
Some old engines see the idea instantly, namely AnMon 5.60, Dragon 4.6, Hermann 2.4 64-bit, Nejmet 3.07, ProDeo 1.5, Ruffian 1.0.5 and SOS 5.1 for Arena; with ProDeo 1.5 returning a drawish evaluation of circa -0.28 and the rest of engines evaluating black more generously.
------------
I also want to note that if you miss 26.- ..., Qd3+! and play 26.- ..., g6 instead, I expected a checkmate by white with Qh6 and Qg7#, completely forgetting that white lacks of king safety and would be mated after 27.- Qh6??, Qg2+:
[pgn][Event ""]
[Site ""]
[Round ""]
[Date "2026.08.15"]
[SetUp "1"]
[FEN "1r2r1k1/5p1p/p4Pp1/6Q1/b1pP3P/2N2q1N/P1PK4/2R4R w - - 0 27"]
[Result "*"]
27.Rb1 (27.Rf1 (27.Qh6?? Qg2+ 28.Nf2 (28.Ne2 (28.Kd1 Qg4+ 29.Kd2 (29.Ne2 Qxe2# 0-1) Qxd4# 0-1) 0-1) 28...Qxf2+ 0-1) *) *[/pgn]
When only Rb1 and Rf1 are reasonable for white.
Regards from Spain.
Ajedrecista.