British Chess Problem Society - The Problemist EG# 18901

[Sean Evans]

[d]Q3b3/1p2q3/1p6/bp5P/1p6/1p6/1P1N1PPp/4NK1k w - - 0 1

Can your chess engine find the answer?

I will post the answer later

Sean

[Ignacio]

I will play 1.Qd8

[MikeGL]

+M17 not sure if that mate in 17 can still be improved.

[Sean Evans]

[pgn]
[Event "British Chess Problem Society"]
[Site "?"]
[Date "2012.??.??"]
[Round "?"]
[White ""]
[Black ""]
[Result "1-0"]
[SetUp "1"]
[FEN "Q3b3/1p2q3/1p6/bp5P/1p6/1p6/1P1N1PPp/4NK1k w - - 0 1"]
[PlyCount "21"]
[EventDate "2012"]

{The Problemist/7 EG#18901.} 1. Qd8 (1. f3 $2 Qc5 2. Ne4 Qc4+ 3. Kf2 Qd4+) 1...
Qxd8 2. Ne4 Qh4 3. Ng3+ Qxg3 4. fxg3 Bxh5 5. Kf2 (5. g4 $2 Bxg4 6. Kf2 Be2 7.
g3 Bg4) 5... Bg4 6. Nd3 Be2 7. Nf4 Bg4 8. Nd5 Bf3 9. Nc7 Bg4 10. Na8 Bf5 11. g4 {any move mate in 7}
1-0
[/pgn]

[MikeGL]

Thanks for your main line below.

I think more difficult for engines after 1.Qd8 there's this
1...Qe6 which is think complicates things a bit compared to the main line.
Very nice puzzle, btw.

[pgn]
[Event "British Chess Problem Society"]
[Site "?"]
[Date "2012.??.??"]
[Round "?"]
[White ""]
[Black ""]
[Result "1-0"]
[SetUp "1"]
[FEN "Q3b3/1p2q3/1p6/bp5P/1p6/1p6/1P1N1PPp/4NK1k w - - 0 1"]
[PlyCount "21"]
[EventDate "2012"]

{The Problemist/7 EG#18901.} 1. Qd8 (1. f3 $2 Qc5 2. Ne4 Qc4+ 3. Kf2 Qd4+) 1...
Qxd8 2. Ne4 Qh4 3. Ng3+ Qxg3 4. fxg3 Bxh5 5. Kf2 (5. g4 $2 Bxg4 6. Kf2 Be2 7.
g3 Bg4) 5... Bg4 6. Nd3 Be2 7. Nf4 Bg4 8. Nd5 Bf3 9. Nc7 Bg4 10. Na8 Bf5 11. g4 {any move mate in 7}
1-0
[/pgn]

[Ajedrecista]

Hello Sean:

[pgn]
[Event "British Chess Problem Society"]
[Site "?"]
[Date "2012.??.??"]
[Round "?"]
[White ""]
[Black ""]
[Result "1-0"]
[SetUp "1"]
[FEN "Q3b3/1p2q3/1p6/bp5P/1p6/1p6/1P1N1PPp/4NK1k w - - 0 1"]
[PlyCount "21"]
[EventDate "2012"]

{The Problemist/7 EG#18901.} 1. Qd8 (1. f3 $2 Qc5 2. Ne4 Qc4+ 3. Kf2 Qd4+) 1...
Qxd8 2. Ne4 Qh4 3. Ng3+ Qxg3 4. fxg3 Bxh5 5. Kf2 (5. g4 $2 Bxg4 6. Kf2 Be2 7.
g3 Bg4) 5... Bg4 6. Nd3 Be2 7. Nf4 Bg4 8. Nd5 Bf3 9. Nc7 Bg4 10. Na8 Bf5 11. g4 {any move mate in 7}
1-0
[/pgn]

Excellent problem! However, Chest 5.2 slightly disagrees, starting with this position:

[d]N7/1p6/1p6/bp6/1p4b1/1p4P1/1P3KPp/7k b - - 11 10

From here, Chest thinks that 10.- ..., Bf3 and 10.- ..., Bh3 lead to a move more than 10.- ..., Bf5. Chest analysis:

Code: Select all

FEN: N7/1p6/1p6/bp6/1p4b1/1p4P1/1P3KPp/7k b - - 11 10 

ChestUCI_52:
FEN: N7/1p6/1p6/bp6/1p4b1/1p4P1/1P3KPp/7k b - -   (5+9)
Stellungs-Analyse:  S:1/9
Suche nach Matt in -10 ...  (Hash=64MB)
Suche abgeschlossen ...  (Zeit=4.64s)
Matt in -9 gefunden !  (9 Lösungen in 00:04)
  8/9	00:05	   1.997.470	430.489	-M8	Bg4c8 g3g4 Bc8d7 Na8c7 Bd7c6 g4g5 Bc6d7 Nc7d5 Bd7f5 Nd5e3 Bf5d3 g5g6 Bd3e4 Ne3f1 Be4f5 Nf1g3+
  8/9	00:05	   1.997.470	430.489	-M8	Bg4d7 g3g4 Bd7e8 Na8c7 Be8c6 g4g5 Bc6d7 Nc7d5 Bd7f5 Nd5e3 Bf5d3 g5g6 Bd3e4 Ne3f1 Be4f5 Nf1g3+
  8/9	00:05	   1.997.470	430.489	-M8	Bg4e6 g3g4 Be6g8 Na8c7 Bg8f7 g4g5 Bf7g8 Nc7e8 Bg8f7 Ne8f6 Bf7g6 g2g4 Bg6h7 Nf6h5 Bh7g6 Nh5g3+
  8/9	00:05	   1.997.470	430.489	-M8	Bg4f5 g3g4 Bf5g6 Na8c7 Bg6f7 g4g5 Bf7g8 Nc7e8 Bg8f7 Ne8f6 Bf7g6 g2g4 Bg6h7 Nf6h5 Bh7g6 Nh5g3+
  8/9	00:05	   1.997.470	430.489	-M8	Bg4d1 g3g4 Bd1f3 Na8c7 Bf3c6 g4g5 Bc6d7 Nc7d5 Bd7f5 Nd5e3 Bf5d3 g5g6 Bd3e4 Ne3f1 Be4f5 Nf1g3+
  8/9	00:05	   1.997.470	430.489	-M8	Bg4e2 g3g4 Be2f3 Na8c7 Bf3c6 g4g5 Bc6d7 Nc7d5 Bd7f5 Nd5e3 Bf5d3 g5g6 Bd3e4 Ne3f1 Be4f5 Nf1g3+
  8/9	00:05	   1.997.470	430.489	-M8	Bg4h5 g3g4 Bh5g6 Na8c7 Bg6f7 g4g5 Bf7g8 Nc7e8 Bg8f7 Ne8f6 Bf7g6 g2g4 Bg6h7 Nf6h5 Bh7g6 Nh5g3+
  9/9	00:05	   1.997.470	430.489	-M9	Bg4h3 g3g4 Bh3xg2 Na8c7 Bg2c6 Nc7e6 Bc6d7 Ne6g5 Bd7c6 Ng5h7 Bc6e8 Nh7f6 Be8g6 g4g5 Bg6h7 Nf6h5 Bh7g6 Nh5g3+
  9/9	00:05	   1.997.470	430.489	-M9	Bg4f3 g3g4 Bf3xg2 Na8c7 Bg2c6 Nc7e6 Bc6d7 Ne6g5 Bd7c6 Ng5h7 Bc6e8 Nh7f6 Be8g6 g4g5 Bg6h7 Nf6h5 Bh7g6 Nh5g3+

SF 8 agrees with Chest in that position.

Regards from Spain.

Ajedrecista.

[Ignacio]

After 1.Qd8 Qxd8 Chest says mate in 18.

[Sean Evans]

After 1.Qd8 Qxd8 Chest says mate in 18.

Which agrees with the solution I posted above

A difficult chess study for chess engines to solve!

Sean

[Nordlandia]

The study can be found in EG | No. 192 - Vol. XIX - April 2013 Supplement.

Page 160.