Anti-Engine Puzzle

towforce · Post by **towforce** » Mon Mar 08, 2021 2:43 pm

peter wrote: ↑Mon Mar 08, 2021 1:45 pm
Paloma wrote: ↑Mon Mar 08, 2021 4:09 am [d]8/8/2k5/3N4/8/4N1p1/4Kprp/B5bn w - - 0 1
[pgn][Event "Outskirts?"]
[Site "?"]
[Date "2020.09.14"]
[Round "?"]
[White "White, to Move"]
[Black "and Win"]
[Result "1-0"]
[SetUp "1"]
[FEN "8/8/2k5/3N4/8/4N1p1/4Kprp/B5bn w - - 0 1"]
[PlyCount "95"]

1. Kf1 Kc5 2. Nf6 Kd6 3. Nfd5 Kc5 4. Nf4 Kb4 5. Bb2 Kb5 6. Ba3 Kc6 7. Ne6 Kd7
8. Nd4 Ke8 9. Bd6 Kd7 10. Nc4 Ke8 11. Ne5 Kd8 12. Ne6+ Ke8 13. Ng7+ Kd8 14.
Ne6+ Kc8 15. Nc5 Kd8 16. Nf7+ Ke8 17. Ne5 Kd8 18. Nc6+ Kc8 19. Ne7+ Kd8 20.
Nc6+ Ke8 21. Bb8 Kf7 22. Be5 Kg6 23. Ne7+ Kf7 24. Nc8 Kg6 25. Nd6 Kg5 26. Ne6+
Kh5 27. Nf5 Kg6 28. Nd6 Kh7 29. Nf8+ Kg8 30. Ng6 Kh7 31. Ne7 Kh6 32. Nf7+ Kh7
33. Ng5+ Kh6 34. Bf6 Kh5 35. Nf7 Kg4 36. Bg5 Kf3 37. Nd6 Kg4 38. Bc1 Kh5 39.
Nc4 Kg4 40. Ne5+ Kh4 41. Bd2 Kh5 42. Nd5 Kh4 43. Nf6 Kh3 44. Nc6 Kh4 45. Nd4
Kh3 46. Ne6 Kh4 47. Bg5+ Kh3 48. Nf4# 1-0

[/pgn]

DTM I'm not sure about, got it just by playing out and it's too long to keep it in hash easily at Backward, but it should work within 50 moves boundary, which is the main problem as for engines' output, I guess, getting once and again 50 moves- draw into search- horizon before mating score arises.
If it's a study, which I don't know, neither the author, if it is one, 50 moves wouldn't count, studies don't have such a boundary. Found it once at Outskirts- Forum from a user I don't know neither and without solution too.
Maybe engines with 50 moves rule to be switched off would get it soon, not as for DTM but as for White wins- eval.

Edit: For those registered at Outskirts, here's what Peter Grayson wrote about the problem there then:

http://outskirts.altervista.org/forum/v ... ost#p19077

If this is a valid solution, then it's a tricky one for engines because an engine is going to want to take the rook, letting the bishop out and probably making the mate impossible.

It might be possible to prove the above solution works by induction: probably by proving that it's possible to move the king to the edge, and then to move it around the edge.

peter · Post by **peter** » Mon Mar 08, 2021 3:14 pm

towforce wrote: ↑Mon Mar 08, 2021 2:43 pm If this is a valid solution,

...it should be possible to keep it in hash backward with enough hardware- time.

Rented some 128 core machine in chessbase cloud just now for a short time, pity only 32G hash, 64 or 128 would be much better of course.
But as for the second half of the moves it's no problem to keep the mating- score in hash:

Position after 24 moves from above:

8/8/2k5/3N4/8/4N1p1/4Kprp/B5bn w - - 0 1

1. Kf1 Kc5 2. Nf6 Kd6 3. Nfd5 Kc5 4. Nf4 Kb4 5. Bb2 Kb5 6. Ba3 Kc6 7. Ne6 Kd7
8. Nd4 Ke8 9. Bd6 Kd7 10. Nc4 Ke8 11. Ne5 Kd8 12. Ne6+ Ke8 13. Ng7+ Kd8 14.
Ne6+ Kc8 15. Nc5 Kd8 16. Nf7+ Ke8 17. Ne5 Kd8 18. Nc6+ Kc8 19. Ne7+ Kd8 20.
Nc6+ Ke8 21. Bb8 Kf7 22. Be5 Kg6 23. Ne7+ Kf7 24. Nc8 Kg6

[d]2N5/8/6k1/2N1B3/8/6p1/5prp/5Kbn w - - 0 1
Analysis by 128 Core Stockfish 13-Dev+NNUE Syzygy:

25.Sd6 Kh7 26.Se6 Kg8 27.La1 Kh7 28.Sf8+ Kg8 29.Sg6 Kh7 30.Se7 Kh6 31.Sf7+ Kh7 32.Sg5+ Kh6 33.Lf6 Kh5 34.Sf7 Kg4 35.Lg5 Kf3 36.Sd6 Kg4 37.Lc1 Kh5 38.Sf7 Kg4 39.Se5+ Kh4 40.Sg8 Kh3 41.Sf6 Kh4 42.Sg6+ Kh3 43.Sf4+ Kh4 44.Se6 Kh3 45.Le3 Kh4 46.Lg5+ Kh3 47.Sf4#
+- (#23) Tiefe: 106/46 00:01:18 38920MN, tb=2351812

SF 11 as engine would be somewhat better, it's mate search being some faster than the one after NNUE- versions of dev. 12+.
And Syzygys should be switched off too of course regards

Paloma · Post by **Paloma** » Mon Mar 08, 2021 3:20 pm

[pgn]
[Event "White to mate or draw?"]
[Site "Newport, South Wales"]
[Date "2020.08.21"]
[Round "?"]
[White "Peter Grayson"]
[Black "?"]
[Result "1-0"]
[SetUp "1"]
[FEN "8/8/2k5/3N4/8/4N1p1/4Kprp/B5bn w - - 0 1"]
[PlyCount "91"]

1. Kf1 Kd6 2. Bd4 Kc6 3. Nc3 Kd6 4. Nc4+ Ke6 5. Be5 Kd7 6. Na5 Ke6 7. Bb8 Kd7 8. Nd5 Ke6 9. Nb6 Kf5 10. Nac4 Ke4 11. Be5 Kf5 12. Bc3 Ke6 13. Bd4 Ke7 14. Be5 Ke6 15. Bc7 Kf5 16. Nd2 Ke6 17. Ne4 Kf5 18. Nc5 {#30} Kg4 19. Nc4 Kf3 20. Be5 Kg4 21. Nd6 Kf3 22. Bd4 Kg4 23. Ne6 Kh5 24. Bf6 Kg6 25. Be7 Kh5 26. Nf4+ Kg4 27. Ng6 Kh5 28. Ne5 Kh6 29. Nf5+ Kh5 30. Ng7+ Kh6 31. Bf6 Kh7 32. Nf5 Kg8 33. Bg7 Kh7 34. Bh6 Kg8 35. Ne7+ Kh8 36. Ng4 Kh7 37. Bf8 Kh8 38. Ne3 Kh7 39. N3f5 Kh8 40. Bg7+ Kh7 41. Bh6 Kh8 42. Bf8 Kh7 43. Ne3 Kh8 44. Ng4 Kh7 45. Nf6+ Kh8 46. Ng6# 1-0

[/pgn]
18.Nc5 is mate in 30

peter · Post by **peter** » Mon Mar 08, 2021 3:31 pm

Paloma wrote: ↑Mon Mar 08, 2021 3:20 pm [pgn]
[Event "White to mate or draw?"]
[Site "Newport, South Wales"]
[Date "2020.08.21"]
[Round "?"]
[White "Peter Grayson"]
[Black "?"]
[Result "1-0"]
[SetUp "1"]
[FEN "8/8/2k5/3N4/8/4N1p1/4Kprp/B5bn w - - 0 1"]
[PlyCount "91"]

1. Kf1 Kd6 2. Bd4 Kc6 3. Nc3 Kd6 4. Nc4+ Ke6 5. Be5 Kd7 6. Na5 Ke6 7. Bb8 Kd7 8. Nd5 Ke6 9. Nb6 Kf5 10. Nac4 Ke4 11. Be5 Kf5 12. Bc3 Ke6 13. Bd4 Ke7 14. Be5 Ke6 15. Bc7 Kf5 16. Nd2 Ke6 17. Ne4 Kf5 18. Nc5 {#30} Kg4 19. Nc4 Kf3 20. Be5 Kg4 21. Nd6 Kf3 22. Bd4 Kg4 23. Ne6 Kh5 24. Bf6 Kg6 25. Be7 Kh5 26. Nf4+ Kg4 27. Ng6 Kh5 28. Ne5 Kh6 29. Nf5+ Kh5 30. Ng7+ Kh6 31. Bf6 Kh7 32. Nf5 Kg8 33. Bg7 Kh7 34. Bh6 Kg8 35. Ne7+ Kh8 36. Ng4 Kh7 37. Bf8 Kh8 38. Ne3 Kh7 39. N3f5 Kh8 40. Bg7+ Kh7 41. Bh6 Kh8 42. Bf8 Kh7 43. Ne3 Kh8 44. Ng4 Kh7 45. Nf6+ Kh8 46. Ng6# 1-0

[/pgn]
18.Nc5 is mate in 30

Which would make it 48 all together, that's what I have in my .pgn (see my first posting).

http://talkchess.com/forum3/viewtopic.p ... 43#p886343

But now show proof, that there aren't any wrong moves up to 18th regards

Ignacio · Post by **Ignacio** » Mon Mar 08, 2021 3:37 pm

With P1/X6, Chest says Mate in 51.

Vinvin · Post by **Vinvin** » Mon Mar 08, 2021 4:10 pm

It's a job for Sting-SF.
After some learning :

Code: Select all

Sting-sf-27:
...
 34+	00:04	 42 873 935	9 031 795	+3,95	1.Kf1
 34+	00:04	 42 890 763	9 025 833	+4,04	1.Kf1
 34+	00:04	 43 008 713	9 020 283	+4,16	1.Kf1 Kc5 2.Bg7 Kd6 3.Bf8+ Kc6 4.Nb4+ Kc7 5.Nd3 Kb6 6.Ne5 Ka6 7.Bd6 Kb7 8.Bc5 Kc7 9.Bf8 Kb7 10.N3c4 Ka7 11.Ba3 Ka6 12.Be7 Kb7 13.Bd6
 34+	00:04	 43 045 410	9 010 971	+4,34	1.Kf1 Kc5 2.Bg7 Kd6 3.Bf8+ Kc6 4.Nb4+ Kc7 5.Nd3 Kb6 6.Ne5 Ka6 7.Bd6 Kb7 8.Bc5 Kc7 9.Bf8 Kb7 10.N3c4 Ka7 11.Ba3 Ka6 12.Be7 Kb7 13.Bd6 Ka7 14.Bf8
 34+	00:04	 43 109 740	9 005 585	+4,61	1.Kf1 Kc5 2.Bg7 Kd6 3.Bf8+ Kc6 4.Nb4+ Kc7 5.Nd3 Kb6 6.Ne5 Ka6 7.Bd6 Kb7 8.Bc5 Kc7 9.Bf8 Kb7 10.N3c4 Ka7 11.Ba3 Ka6 12.Be7 Kb7 13.Bd6 Ka7 14.Bf8 Kb7 15.Ne3
 34	00:08	 80 457 511	9 519 345	+3,87	1.Kf1 Kc5 2.Bg7 Kd6 3.Bf8+ Kc6 4.Nb4+ Kc7 5.Nd3 Kb6 6.Ne5 Ka6 7.Bd6 Kb7 8.Bc5 Kc7 9.Bf8 Kb7 10.N3c4 Ka7 11.Ba3 Ka6 12.Ne3 Kb6 13.Be7
 35+	00:08	 80 603 563	9 512 989	+3,95	1.Kf1
 35+	00:08	 80 620 710	9 508 280	+4,04	1.Kf1
 35+	00:08	 80 645 835	9 505 638	+4,16	1.Kf1 Kc5 2.Bg7 Kd6 3.Bf8+ Kc6 4.Nb4+ Kb5 5.Be7 Kb6 6.Nd3 Kc7 7.Bf8 Kb6 8.Ne5 Kc7 9.Nd5+ Kb8 10.Be7 Kb7 11.Ne3 Kb6 12.Ba3 Kb7 13.Bc5 Kc7 14.Bf8 Kb7 15.Ba3
 35+	00:08	 80 650 214	9 503 913	+4,34	1.Kf1 Kc5 2.Bg7 Kd6 3.Bf8+ Kc6 4.Nb4+ Kb5 5.Be7 Kb6 6.Nd3 Kc7 7.Bf8 Kb6 8.Ne5 Kc7 9.Nd5+ Kb8 10.Be7 Kb7 11.Ne3 Kb6 12.Ba3 Kb7 13.Bc5 Kc7 14.Bf8 Kb7 15.Ba3 Ka6 16.Bd6 Kb7 17.Nd5
 35+	00:10	 98 223 021	9 597 715	+4,61	1.Kf1 Kc5 2.Bg7 Kd6 3.Nb4 Kd7 4.Be5 Kc8 5.Nd3 Kd7 6.Nc4 Kc6 7.Bf6 Kd5 8.Nde5 Ke6 9.Bg7 Kd5 10.Bf8 Kd4 11.Ba3 Ke4 12.Nc6 Kf3 13.Be7 Ke4 14.Bf8 Kf5 15.Bd6 Kg4 16.Bc5 Kf3 17.Bf8
 35	00:16	 150 179 016	9 266 305	+4,04	1.Kf1 Kc5 2.Bg7 Kd6 3.Nb4 Kd7 4.Be5 Kc8 5.Nd3 Kd7 6.Nc4 Kc6 7.Bf6 Kd5 8.Nde5 Kd4 9.Bg7 Kc5 10.Bf8+ Kb5 11.Bd6 Ka6 12.Be7 Kb7 13.Bd8 Ka7 14.Nd6 Ka6 15.Nd3 Ka7 16.Nf4 Kb8 17.Nxg2 Ka7 18.Ba5 Ka8 19.Bb4 Kb8 20.Ne4 Kc7
 36+	00:16	 150 824 697	9 251 913	+4,16	1.Kf1
 36+	00:16	 152 295 528	9 236 749	+4,28	1.Kf1 Kc5 2.Bg7 Kd6 3.Bf8+ Kc6 4.Nb4+ Kb5 5.Be7 Kb6 6.Nd3 Kc7 7.Bf8 Kb6 8.Ne5 Kc7 9.N3c4 Kb7 10.Bb4 Ka7 11.Ba5 Ka6 12.Bc7 Kb7 13.Bd8 Ka7 14.Nd6 Ka6 15.Nd3 Ka7 16.Nc4 Kb7 17.Be7
 36+	00:16	 155 668 549	9 204 076	+4,46	1.Kf1 Kc5 2.Bg7 Kd6 3.Bf8+ Kc6 4.Nb4+ Kb5 5.Ned5 Ka4 6.Nc7 Kb3 7.Bd6 Kc4 8.Nbd5 Kd4 9.Nb6 Ke4 10.Ne6 Ke3 11.Nc5
 36	00:25	 242 531 057	9 356 186	+4,04	1.Kf1 Kc5 2.Bg7 Kd6 3.Bf8+ Kc6 4.Nb4+ Kb5 5.Bd6 Ka5 6.Nd3 Kb6 7.Be7 Kc6 8.Ne5+ Kc7 9.N3c4 Kb7 10.Bg5 Ka6 11.Bf6 Kb7 12.Nd3 Ka7 13.Be7 Ka6
 37	00:44	 429 101 340	9 688 447	+4,04	1.Kf1 Kc5 2.Bg7 Kd6 3.Bf8+ Kc6 4.Nb4+ Kb5 5.Bd6 Ka5 6.Nd3 Kb6 7.Be7 Kc6 8.Ne5+ Kc7 9.N3c4 Kb7 10.Bg5 Ka6 11.Be3 Kb7 12.Bc5 Ka8 13.Nd3 Kb7 14.Ne3 Ka6 15.Nb4+ Kb5 16.Be7
 38+	00:47	 454 317 622	9 660 166	+4,12	1.Kf1
 38+	00:47	 454 323 504	9 659 880	+4,20	1.Kf1
 38+	00:47	 454 361 946	9 659 260	+4,32	1.Kf1 Kc5 2.Bg7 Kd6 3.Nf4 Kd7 4.Nd3 Ke6 5.Nc4 Kf5 6.Nde5 Ke6 7.Bf8 Kd5 8.Bd6 Ke4 9.Nc6 Kd5 10.N6a5 Ke6 11.Bc5 Kd7 12.Bb4 Ke6 13.Ne3 Ke5 14.Nac4+ Kd4 15.Bf8 Ke4 16.Bc5 Kf4 17.Nd5+ Kf5 18.Ndb6 Kg6 19.Na5 Kf5 20.Bd6 Kg6 21.Nac4
 38+	00:47	 454 428 202	9 657 999	+4,50	1.Kf1 Kc5 2.Bg7 Kd6 3.Nf4 Kd7 4.Nd3 Ke6 5.Nc4 Kf5 6.Nde5 Ke6 7.Bf8 Kd5 8.Bd6 Ke4 9.Nc6 Kd5 10.N6a5 Ke6 11.Bc5 Kd7 12.Bb4 Ke6 13.Ne3 Ke5 14.Nac4+ Kd4 15.Bf8 Ke4 16.Bc5 Kf4 17.Nd5+ Kf5 18.Ndb6 Kg6 19.Na5 Kf5 20.Nbc4
 38	00:56	 547 762 231	9 745 965	+4,04	1.Kf1 Kc5 2.Bg7 Kd6 3.Nf4 Kd7 4.Nd3 Ke6 5.Nc4 Kd7 6.Bf8 Kc6 7.Nde5+ Kb7 8.Bc5 Ka8 9.Nd3 Kb7 10.Bd6 Ka6 11.Nb4+ Kb7 12.Be7 Kb8 13.Nd3 Kb7 14.Ne3 Kc7 15.Nb4 Kb6 16.Nd3
 39	01:09	 675 875 724	9 754 867	+4,04	1.Kf1 Kc5 2.Bg7 Kd6 3.Nf4 Kd7 4.Nd3 Ke6 5.Nc4 Kd7 6.Bf8 Kc6 7.Nde5+ Kb7 8.Bc5 Ka8 9.Nd3 Kb7 10.Bd6 Ka6 11.Nb4+ Kb7 12.Be7
 40+	01:15	 737 939 015	9 746 658	+4,12	1.Kf1
 40+	01:15	 737 955 774	9 746 236	+4,20	1.Kf1
 40+	01:15	 737 959 524	9 746 028	+4,32	1.Kf1 Kc5 2.Nf4 Kb5 3.Nd3 Kc6 4.Bd4 Kb5 5.Ne5 Ka6 6.N3c4 Kb7 7.Nd6+ Kb8 8.Be3 Ka8 9.Ndc4
 40+	01:15	 738 369 296	9 744 747	+4,50	1.Kf1 Kc5 2.Nf4 Kb5 3.Nd3 Kc6 4.Bd4 Kb5 5.Ne5 Ka6 6.N3c4 Kb7 7.Nd6+ Kb8 8.Be3 Ka8 9.Bb6

Ignacio · Post by **Ignacio** » Mon Mar 08, 2021 4:11 pm

FEN: 8/8/2k5/3N4/8/4N1p1/4Kprp/B5bn w - - 0 1

Chest 5.2:
FEN: 8/8/2k5/3N4/8/4N1p1/4Kprp/B5bn w - - (4+7)
Position-Analysis: C0/R0/K6/P2/X9 W:4/26
Search for 1. Special-Mate [C14/R0/K0/P1/X0] in 126 ... (Hash=2044MB)
46 06:27 553.529.985 1.433.413 +M46 Re2-f1
Search completed ... (Time=387.13s)
Mate in 46 found ! (1. Solution in 06:27)
46/46 06:27 554.718.783 1.432.907 +M46 Re2-f1 Rc6-c5 Cd5-c7 Rc5-c6 Aa1-e5 Rc6-b6 Ce3-d5+ Rb6-c6 Cd5-f6 Rc6-b6 Cc7-e6 Rb6-b7 Ae5-f4 Rb7-a7 Ce6-d8 Ra7-a8 Cf6-d7 Ra8-a7 Af4-b8+ Ra7-a8 Ab8-c7 Ra8-a7 Cd7-b6 Ra7-a6 Cb6-c8 Ra6-b5 Ac7-b6 Rb5-c4 Cc8-e7 Rc4-b5 Ab6-a7 Rb5-a5 Ce7-c8 Ra5-b5 Cc8-d6+ Rb5-a5 Cd8-e6 Ra5-a6 Aa7-c5 Ra6-a5 Ce6-c7 Ra5-a4 Cc7-a6 Ra4-a5 Ca6-b8 Ra5-a4 Cb8-c6 Ra4-b3 Ac5-b4 Rb3-c2 Cc6-d4+ Rc2-d3 Cd4-e6 Rd3-e3 Ab4-c3 Re3-d3 Ac3-d4 Rd3-d2 Ce6-c5 Rd2-c2 Cd6-c4 Rc2-c1 Cc4-e3 Rc1-d2 Ce3-d5 Rd2-c2 Cd5-b4+ Rc2-d2 Cc5-b3+ Rd2-d1 Cb3-a5 Rd1-c1 Ca5-c4 Rc1-d1 Ad4-e5 Rd1-c1 Ae5-c3 Rc1-d1 Cc4-a3 Rd1-c1 Cb4-d3+ Rc1-d1 Cd3-b2+ Rd1-c1 Cb2-c4 Rc1-d1 Ac3-d4 Rd1-c1 Ad4-e3+ Rc1-d1 Cc4-b2+

Jouni · Post by **Jouni** » Mon Mar 08, 2021 5:41 pm

128 core SF is waste of power. 6 core Crystal

:

1.Nd6 Kh6 2.Ne6 Kg6 3.Nf8+ Kh6 4.Bb2 Kg5 5.Bd4 Kf4 6.Ne6+ Kf3 7.Ba7 Kg4 8.Be3 Kf3 9.Bc1 Kg4 10.Nf8 Kh5 11.Bd2 Kg4 12.Nd7 Kh5 13.Ne5 Kh4 14.Ne4 Kh3 15.Nf6 Kh4 16.Bf4 Kh3 17.Nf7 Kh4 18.Nd8 Kh3 19.Ne6 Kh4 20.Bg5+ Kh3 21.Nf4#
+- (#21) Depth: 39/41 00:00:06 118mN, tb=372170

But yes Chest is fast in this one.

peter · Post by **peter** » Mon Mar 08, 2021 6:19 pm

Ignacio wrote: ↑Mon Mar 08, 2021 4:11 pm FEN: 8/8/2k5/3N4/8/4N1p1/4Kprp/B5bn w - - 0 1

Chest 5.2:
FEN: 8/8/2k5/3N4/8/4N1p1/4Kprp/B5bn w - - (4+7)
Position-Analysis: C0/R0/K6/P2/X9 W:4/26
Search for 1. Special-Mate [C14/R0/K0/P1/X0] in 126 ... (Hash=2044MB)
46 06:27 553.529.985 1.433.413 +M46 Re2-f1
Search completed ... (Time=387.13s)
Mate in 46 found ! (1. Solution in 06:27)
46/46 06:27 554.718.783 1.432.907 +M46 Re2-f1 Rc6-c5 Cd5-c7 Rc5-c6 Aa1-e5 Rc6-b6 Ce3-d5+ Rb6-c6 Cd5-f6 Rc6-b6 Cc7-e6 Rb6-b7 Ae5-f4 Rb7-a7 Ce6-d8 Ra7-a8 Cf6-d7 Ra8-a7 Af4-b8+ Ra7-a8 Ab8-c7 Ra8-a7 Cd7-b6 Ra7-a6 Cb6-c8 Ra6-b5 Ac7-b6 Rb5-c4 Cc8-e7 Rc4-b5 Ab6-a7 Rb5-a5 Ce7-c8 Ra5-b5 Cc8-d6+ Rb5-a5 Cd8-e6 Ra5-a6 Aa7-c5 Ra6-a5 Ce6-c7 Ra5-a4 Cc7-a6 Ra4-a5 Ca6-b8 Ra5-a4 Cb8-c6 Ra4-b3 Ac5-b4 Rb3-c2 Cc6-d4+ Rc2-d3 Cd4-e6 Rd3-e3 Ab4-c3 Re3-d3 Ac3-d4 Rd3-d2 Ce6-c5 Rd2-c2 Cd6-c4 Rc2-c1 Cc4-e3 Rc1-d2 Ce3-d5 Rd2-c2 Cd5-b4+ Rc2-d2 Cc5-b3+ Rd2-d1 Cb3-a5 Rd1-c1 Ca5-c4 Rc1-d1 Ad4-e5 Rd1-c1 Ae5-c3 Rc1-d1 Cc4-a3 Rd1-c1 Cb4-d3+ Rc1-d1 Cd3-b2+ Rd1-c1 Cb2-c4 Rc1-d1 Ac3-d4 Rd1-c1 Ad4-e3+ Rc1-d1 Cc4-b2+

Very well, Ignacio!
Knowing the DTM of 46 and your params makes it much easier of course, but I would never have come to C14 on my own, how did you?
And yet at my hardware Chest isn't even near to your time to solution. Did you do some retro analysis too maybe?

peter · Post by **peter** » Mon Mar 08, 2021 6:28 pm

Vinvin wrote: ↑Mon Mar 08, 2021 4:10 pm It's a job for Sting-SF.

If you believe in the eval only.
Not much of a mate in sight, not even in the longest output- line, is there?

Anti-Engine Puzzle

Re: Anti-Engine Puzzle

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Re: Anti-Engine Puzzle

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Re: Anti-Engine Puzzle