Mate in 19

[acase]

There are other moves that win of course but only 1 that leads to Mate in 19:

[d]rnbq2kr/pp1p2pp/1np5/8/3P1B2/P7/6PP/R2Q1RK1 w - - 1 5

[AndrewGrant]

info depth 39 seldepth 79 multipv 1 score cp 1552 time 1013506 nodes 43365329537 nps 42787000 tbhits 0 hashfull 1000 pv d1h5 h7h6 a1e1 d7d5 e1e8 d8e8 h5e8 g8h7 e8e7 h8e8 e7e8 c8g4 f4b8 b6d7 e8e7 a8b8 h2h3 g4e6 e7e6 d7b6 e6e5 b8g8 e5e7 b6c4 e7b7 a7a6 b7c6 h7h8 c6a6 c4d2 f1f2 d2e4 f2f7 e4f6 f7b7 g8d8 a6c6 f6e4 c6g6 d8g8 b7e7 e4d2 g6f7 d2e4 f7e6 e4d2 e6e5 d2b1 e5d5 b1a3 d5e4 a3b5 d4d5

We are on the hunt, but not much success thus far.

[jonkr]

SlowChess Blitz Classic 2.26 (4096 MB hash, 16 threads)
FEN: rnbq2kr/pp1p2pp/1np5/8/3P1B2/P7/6PP/R2Q1RK1 w - - 1 1

[24] M20 00:09.7 124.17M Bh6 d6 Qb3+ Nd5 Qg3 g6 Qg5 Qe8 Rae1 Be6 Rxe6 Nd7 Rxe8+ Rxe8 h4 Rf8 Bxf8 Nxf8 Qd8 Kg7 Qxd6 Kh6 Qe5 Rg8 Rf7 Ne6 Qxe6 Rg7 g4 b5 Qe8 Nf6 Rxf6 Rd7 Qxd7 b4 Qf7 bxa3 Qf8#

Found Bh6 is mate in 20 (or less) pretty quickly, but never resolved to M19 so I can't even say if that is the proper move.

[Jouni]

Crystal goes fast to 20 and stays:

...
5.Bh6 d6 6.Qh5 Be6 7.Rae1 N8d7 8.Rxe6 Nf6 9.Qg5 Qc7 10.Rexf6 Nd5 11.R6f3 Qe7 12.Qg4 a6 13.Rg3 Nf6 14.Qf5 Nh5 15.Qxh5 Rf8 16.Rxf8+ Kxf8 17.Qf5+ Ke8 18.Qc8+ Kf7 19.Rf3+ Qf6 20.Qd7+ Kg6 21.Rg3+ Qg5 22.Rxg5+ Kf6 23.Rxg7 Rg8 24.Qf7#
+- (#20) Depth: 34/41 00:03:26 1476mN, tb=3367
5.Bh6 d6 6.Qh5 Be6 7.Rae1 N8d7 8.Rxe6 Nf6 9.Qg5 Qc7 10.Rexf6 Nd5 11.R6f3 Qe7 12.Qg4 a6 13.Rg3 Nf6 14.Qf5 Nh5 15.Qxh5 Rf8 16.Rxf8+ Kxf8 17.Qf5+ Ke8 18.Qc8+ Kf7 19.Rf3+ Qf6 20.Qd7+ Kg6 21.Rg3+ Qg5 22.Rxg5+ Kf6 23.Rf5+ Kg6 24.Qe6#
+- (#20) Depth: 35/39 00:05:12 2235mN, tb=3367
5.Bh6 d6 6.Qh5 Be6 7.Rae1 N8d7 8.Rxe6 Nf6 9.Qg5 Qc7 10.Rexf6 Nd5 11.R6f3 Qe7 12.Qg4 a6 13.Rg3 Nf6 14.Qf5 Nh5 15.Qxh5 Rf8 16.Rxf8+ Kxf8 17.Qf5+ Ke8 18.Qc8+ Kf7 19.Rf3+ Qf6 20.Qd7+ Kg6 21.Rg3+ Qg5 22.Rxg5+ Kf6 23.Rxg7 Rg8 24.Bg5#
+- (#20) Depth: 36/39 00:07:43 3299mN, tb=3367
5.Bh6 d6 6.Qh5 Be6 7.Rae1 N8d7 8.Rxe6 Nf6 9.Qg5 Qc7 10.Rexf6 Nd5 11.R6f3 Qe7 12.Qg4 a6 13.Rg3 Nf6 14.Qf5 Nh5 15.Qxh5 Rf8 16.Rxf8+ Kxf8 17.Qf5+ Ke8 18.Qc8+ Kf7 19.Rf3+ Qf6 20.Qd7+ Kg6 21.Rg3+ Qg5 22.Rxg5+ Kf6 23.Rxg7 Rg8 24.Bg5#
+- (#20) Depth: 37/39 00:11:37 4989mN, tb=3367
5.Bh6 d6 6.Qh5 Be6 7.Rae1 N8d7 8.Rxe6 Nf6 9.Qg5 Qc7 10.Rexf6 Nd5 11.R6f3 Qe7 12.Qg4 a6 13.Rg3 Nf6 14.Qf5 Nh5 15.Qxh5 Rf8 16.Rxf8+ Kxf8 17.Qf5+ Ke8 18.Qc8+ Kf7 19.Rf3+ Qf6 20.Qd7+ Kg6 21.Rg3+ Qg5 22.Rxg5+ Kf6 23.Rxg7 Rg8 24.Bg5#
+- (#20) Depth: 38/42 00:18:55 8152mN, tb=3383

[peter]

There are other moves that win of course but only 1 that leads to Mate in 19:

[d]rnbq2kr/pp1p2pp/1np5/8/3P1B2/P7/6PP/R2Q1RK1 w - - 1 5

Is two less then 19 ok too?

[d]rnbq2kr/pp1p2pp/1np5/8/3P1B2/P7/6PP/R2Q1RK1 w - - 0 1
Analysis by Cfish 030820 64 POPCNT NUMA:

5.Bh6 d6 6.Qh5 Be6 7.Rae1 N8d7 8.Rxe6 Nf6 9.Qg5 Qc7 10.Rexf6 Nd5 11.R6f3 Qe7 12.Qg4 b6 13.h4 Rb8 14.h5 c5 15.Bg5 Qe2 16.h6 Re8 17.Be3 Qxf1+ 18.Rxf1 g6 19.Qd7 Re7 20.Qc8+ Re8 21.Qxe8#
+- (#17) Depth: 78/34 00:00:26 643MN

[acase]

[/quote]

Is two less then 19 ok too?


[/quote]


Of course Peter, I wasn't absolutely sure that 19 was the quickest, but that was the best I could do.

[zullil]

Is two less then 19 ok too?


[/quote]


Of course Peter, I wasn't absolutely sure that 19 was the quickest, but that was the best I could do.
[/quote]

Me too, at least with a direct search from the root position. Getting to mate-in-20 was rather quick. But shaving away one move took a long time. Stopped now. so won't be finding mate-in-17.

info depth 106 seldepth 40 multipv 1 score mate 19 nodes 294199187303 nps 32659590 hashfull 1000 tbhits 0 time 9008049 pv f4h6 d7d6 d1h5 c8e6 a1e1 b8d7 e1e6 d7f6 h5g5 d8c7 e6f6 b6d5 f6f3 c7e7 g5f5 d5c3 f3c3 a8f8 f5g4 f8f1 g1f1 g8f7 c3f3 e7f6 g4g7 f7e6 f3f6 e6d5 g7f7 d5d4 f6f4 d4c3 f7c4 c3b2 f4f2 b2a3 h6c1

[Ajedrecista]

Hello:

The proposed lines between mate in 20 and mate in 17 differ in 12. ... a6 and 12. ... b6, respectively. I searched with Chest 5.2 from this discrespancy just after 12. Qg4 (DefenderMoves option checked) but it did not reach the last ply to probe the mate in 17 after 30 minutes or so because I stopped the analysis. Then I tried the position of the previous ply, just after 11. ... Qe7, DefenderMoves option disabled and Special Mate mode. Chest failed to find a mate in 10 from this position with the parameters suggested by Chest, which would have proben the mate in 17 from the root position.

Code: Select all

FEN: r5kr/pp2q1pp/2pp3B/3n2Q1/3P4/P4R2/6PP/5RK1 w - - 3 12 

ChestUCI_52:
FEN: r5kr/pp2q1pp/2pp3B/3n2Q1/3P4/P4R2/6PP/5RK1 w - -   (9+11)
Stellungs-Analyse:  C0/R0/K1/P7/X32   W:8/41
Suche nach Spezial-Matt [C0/R0/K1/P7/X32] in 10 ...  (Hash=512MB)
Suche abgeschlossen ...  (Zeit=525.30s)
Kein Matt in 10 gefunden !  (08:45)

Checking with SF 11 from the same position where I tried Chest:

[d]r5kr/pp2q1pp/2pp3B/3n2Q1/3P4/P4R2/6PP/5RK1 w - -

It quickly returns a mate in 13 at shallow depths < 30, which means a mate in 20 from the root position. If I make the move Qg4, then it does not like ... b6 (the proposed black move for the mate in 17) because it shortens white mate. SF prefers ... a6, ... a5 or ... c5, for example. I would look at 12. ... b6, which looks fishy.

Qf5 by Louis gives the same score than Qg4 according to SF at not incredible search depths.

Regards from Spain.

Ajedrecista.

[peter]

Me too, at least with a direct search from the root position.

So I'm the master of the Forward- Backward, even beating your machine, Louis, when it's stand- alone- computing only. Great day!

[Ignacio]

Hello:

The proposed lines between mate in 20 and mate in 17 differ in 12. ... a6 and 12. ... b6, respectively. I searched with Chest 5.2 from this discrespancy just after 12. Qg4 (DefenderMoves option checked) but it did not reach the last ply to probe the mate in 17 after 30 minutes or so because I stopped the analysis. Then I tried the position of the previous ply, just after 11. ... Qe7, DefenderMoves option disabled and Special Mate mode. Chest failed to find a mate in 10 from this position with the parameters suggested by Chest, which would have proben the mate in 17 from the root position.

Code: Select all

FEN: r5kr/pp2q1pp/2pp3B/3n2Q1/3P4/P4R2/6PP/5RK1 w - - 3 12 

ChestUCI_52:
FEN: r5kr/pp2q1pp/2pp3B/3n2Q1/3P4/P4R2/6PP/5RK1 w - -   (9+11)
Stellungs-Analyse:  C0/R0/K1/P7/X32   W:8/41
Suche nach Spezial-Matt [C0/R0/K1/P7/X32] in 10 ...  (Hash=512MB)
Suche abgeschlossen ...  (Zeit=525.30s)
Kein Matt in 10 gefunden !  (08:45)

Checking with SF 11 from the same position where I tried Chest:

[d]r5kr/pp2q1pp/2pp3B/3n2Q1/3P4/P4R2/6PP/5RK1 w - -

It quickly returns a mate in 13 at shallow depths < 30, which means a mate in 20 from the root position. If I make the move Qg4, then it does not like ... b6 (the proposed black move for the mate in 17) because it shortens white mate. SF prefers ... a6, ... a5 or ... c5, for example. I would look at 12. ... b6, which looks fishy.

Qf5 by Louis gives the same score than Qg4 according to SF at not incredible search depths.

Regards from Spain.

Ajedrecista.

Hi Ajedrecista.
Wrong parameters for Chest.

Regards from Spain too.