Mate in 19 shortened to mate in 17 by The Huntsman 1

[acase]

Here's a mate in 34 from the UPDATED ChestUCI database that The Huntsman 1 shortened to a mate in 23:

[pgn][Event "Mate in 23"] [Site "Columbus, Ohio"] [Date "2024.02.28"] [Round "?"] [White "?"] [Black "?"] [Result "1-0"] [Time "22:51:45"] [TimeControl "0"] [SetUp "1"] [FEN "R1n4k/n1p5/pb1p1N1P/3P3p/7p/p1p1P3/P1P1PP1P/7K w - - 0 1"] [Termination "normal"] [PlyCount "45"] [WhiteType "program"] [BlackType "program"] [Comment "bm #34;"] 1. Rb8 {+M23/119 2 The Huntsman 1 bmi2} h3 2. Kg1 Bc5 (2. .. h4 3. Kh1 {+M21/81 11 The Huntsman 1 bmi2} a5 4. Kg1 Bc5 5. Rb1 Nb6 6. Kh1 Nd7 7. Nxd7 Bxe3 8. fxe3 Kh7 9. Rb7 Nb5 10. Rxb5 Kxh6 11. Rb8 Kg7 12. Rf8 Kg6 13. Kg1 a4 14. Kf2 Kg7 15. Kf3 Kh7 16. Kg4 Kg6 17. Kf4 Kh7 18. Kg5 Kg7 19. e4 c6 20. dxc6 d5 21. exd5 Kh7 22. Kf6 Kh6 23. Rh8#) (2. .. a5 3. Kh1 {+M21/73 2 The Huntsman 1 bmi2} h4 4. Kg1 Bc5 5. Rb1 Nb6 6. Kh1 Nd7 7. Nxd7 Bxe3 8. fxe3 Kh7 9. Rb7 Nb5 10. Rxb5 Kxh6 11. Rb8 Kg7 12. Rf8 Kg6 13. Kg1 a4 14. Kf2 Kg7 15. Kf3 Kh7 16. Kf4 Kg6 17. Rf6+ Kh7 18. Nf8+ Kg8 19. Kf5 Kg7 20. Ne6+ Kh7 21. Rf7+ Kg8 22. Kg6 Kh8 23. Rf8#) 3. Rb1 Nb6 4. Kh1 Nd7 5. Nxd7 Kh7 6. Nxc5 dxc5 7. d6 cxd6 8. Rb7+ Kxh6 9. Rxa7 d5 10. Rxa6+ Kg5 11. Rxa3 Kf5 12. Rb3 d4 13. exd4 cxd4 14. Kg1 Ke6 15. a4 h4 16. a5 Kd7 17. a6 d3 18. exd3 Kd6 19. a7 Kc7 20. a8=Q Kd7 21. Qa6 Ke7 22. Rb7+ Kd8 23. Qa8# 1-0 [/pgn]

[Paloma]

[pgn][Event "?"]
[Site "?"]
[Date "2024.02.29"]
[Round "?"]
[White "23# ?"]
[Black "?"]
[Result "1-0"]
[Annotator "?"]
[SetUp "1"]
[FEN "R1n4k/n1p5/pb1p1N1P/3P3p/7p/p1p1P3/P1P1PP1P/7K w - - 0 1"]
[PlyCount "45"]
[SourceVersionDate "2024.02.29"]

1. Rb8 $1 {26#} h3 $1 2. Kg1 {25#} Bc5 $6 (2... h4 $1 3. Kh1 {22#} a5 4. Kg1 Bc5 5. Rb1 {20#} Nb6 6. Kh1 Nd7 7. Nxd7 {18#} Kh7 (7... Bxe3 $2 8. fxe3 {16#} Kh7 $1 9. Rb7 {15#}) 8. Nxc5 {17#}) (2... a5 $1 3. Kh1 {24#} a4 (3... h4 4. Kg1 {21#} Bc5 5. Rb1 Nb6 6. Kh1) 4. Kg1 Bc5 5. Kf1 {22#} Bb6 6. f4 {21#}) 3. Rb1 {22#!} Nb6 4. Kh1 {21#} Nd7 5. Nxd7 Kh7 6. Nxc5 {19#} dxc5 $2 (6... Kxh6 $1 7. Ne6 {18#} Kg6 8. Rb8 Kf5 (8... Kf6 9. Nxc7 {16#}) 9. Nxc7 {15#} Kf6 10. f4 Nb5 11. Nxb5 axb5 12. e4) 7. d6 {17#} cxd6 8. Rb7+ Kxh6 9. Rxa7 {15#} d5 10. Rxa6+ Kg5 11. Rxa3 Kf5 12. Rb3 $1 {12#} d4 13. exd4 cxd4 14. Kg1 Ke6 15. a4 h4 16. a5 Kd7 17. a6 d3 18. exd3 Kd6 19. a7 Kc7 20. a8=Q Kd7 21. Qa6 Ke7 22. Rb7+ Kd8 23. Qa8# 1-0

[/pgn]
It's a mate in 26
Best is 2...a5 3.Kh1 a4 4.Kg1 Bc5 5.Kf1 22#

[Ajedrecista]

Hello:

This problem is from the 90s:

https://pdb.dieschwalbe.de/P1402334

The current status in Die Schwalbe problem database is a cook of the original #34 stipulation, improving it to #27. So Andrew's idea to check is 3.- Rb1.

------------

[...]
It's a mate in 26
Best is 2...a5 3.Kh1 a4 4.Kg1 Bc5 5.Kf1 22#

Regarding Paloma's answer, wouldn't it be a #27? If you stop after white's 5th move and claim #22, if I make a shortcut:

• A #1 claim would play black's 5th and white's 6th moves.

• A #2 claim would extend to black's 6th and white's 7th moves.

Hence #22 after white's 5th move should end at white's #27, agreeing on DTM with the former improvement.

Regards from Spain.

Ajedrecista.

[Paloma]

Code: Select all

Regarding Paloma's answer, wouldn't it be a #27? If you stop after white's 5th move and claim #22, if I make a shortcut:

    A #1 claim would play black's 5th and white's 6th moves.

    A #2 claim would extend to black's 6th and white's 7th moves.

Hence #22 after white's 5th move should end at white's #27, agreeing on DTM with the former improvement.

???
I mean 5.Kf1 is a mate in 22

1.Rb8 is mate in 26, 1...h3
2.Kg1 a5! (better as ...Bc5?, because 3.Rb1! is mate in 22, 3...Nb6 4.Kh1 Nd7 5.Nd7 Kh7 6.Nxc5 Kxh6! 7.Ne6! is mate in 18) 6...dxc5? 7.d6! is mate in 17!

3.Kh1 mate in 24 3...a4! (better as 3...h4)
4.Kg1 Bc5
5.Kf1 mate in 22 5...Bb6
6.f4 # in 21

[acase]

Code: Select all

Regarding Paloma's answer, wouldn't it be a #27? If you stop after white's 5th move and claim #22, if I make a shortcut:

    A #1 claim would play black's 5th and white's 6th moves.

    A #2 claim would extend to black's 6th and white's 7th moves.

Hence #22 after white's 5th move should end at white's #27, agreeing on DTM with the former improvement.

???
I mean 5.Kf1 is a mate in 22

1.Rb8 is mate in 26, 1...h3
2.Kg1 a5! (better as ...Bc5?, because 3.Rb1! is mate in 22, 3...Nb6 4.Kh1 Nd7 5.Nd7 Kh7 6.Nxc5 Kxh6! 7.Ne6! is mate in 18) 6...dxc5? 7.d6! is mate in 17!

3.Kh1 mate in 24 3...a4! (better as 3...h4)
4.Kg1 Bc5
5.Kf1 mate in 22 5...Bb6
6.f4 # in 21

Hello, I still think it is a mate in 23 from the root position, and that if Black plays 2...a5 instead of 2...Bc5 it leads to a mate in 22 from the ROOT position. I think there is an improvement for white in your variation at move 5, instead of 5.Kf1, what if we try 5.Rb1!, here's a pgn of my analysis:

[pgn][Event "Mate in 23?"]
[Site "Columbus, Ohio"]
[Date "2024.03.07"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "1-0"]
[Time "09:19:50"]
[TimeControl "0"]
[SetUp "1"]
[FEN "R1n4k/n1p5/pb1p1N1P/3P3p/7p/p1p1P3/P1P1PP1P/7K w - - 0 1"]
[Termination "normal"]
[PlyCount "9"]
[WhiteType "program"]
[BlackType "program"]

1. Rb8 h3 2. Kg1 a5 3. Kh1 a4 4. Kg1 Bc5 5. Kh1? (5. Rb1! Nb6 6. Kh1 Nd7 7. Nxd7 Kh7 8. Nxc5 Kxh6 9. Ne6 Nc8 (9. ..
Kg6 10. Rb8 c6 11. Ra8 cxd5 12. Rxa7 d4 13.
Nxd4 Kf6 14. f4 Kg6 15. e4 h4 16. Kg1 Kf6 17. Kf2 Kg6 18. Kf3 Kf6 19. Kg4
Kg6 20. Ne6 d5 21. Nf8+ Kf6 22. e5#) (9. .. c6 10. Rb7 Nc8 11. Rg7 cxd5 12. f4 Ne7 13. Rxe7 Kg6 14. Nd4 Kf6 15. Rd7
Kg6 16. f5+ Kf6 17. Kg1 h4 18. Kf2 Kg5 19. Kf3 Kf6 20. Kg4 Ke5 21. Kg5 Ke4
22. Re7#) 10. Rg1 Ne7 (10. .. Nb6 11. Nf8
h4 12. e4 Kh5 13. f4 Nc4 14. Rg6 Ne5 15. Rg7 Ng4 16. Rg5+ Kh6 17. Rxg4 Kh5
18. Rg6 c6 19. f5 cxd5 20. Ne6 dxe4 21. Nf4#) 11. Nf8 h4 12. e4 c6 13. dxc6 Nxc6 14. Rg6+ Kh5 15. f4 Ne5 16. Rg7 d5
17. fxe5 Kh6 18. Rg1 Kh5 19. e6 Kh6 20. e7 d4 21. e8=Q d3 22. Qg6#) 1-0[/pgn]

Let me know if you find something else, thanks.

[Paloma]

Huh, you are right Andrew,

Huntsman hangs often with a higher mate announcement, and after a very long time switched to a shorter mate announcement.
Maybe my Hashtables with 16 GB are too small.

After
5.Rb1 Nb6
6.Kh1 Nd7
7.Nxd7 maybe Bxe3 is better than Kh7
then 8.fxe3 is mate in 16
...Kh7
9.Rb7 Nb5
10.Rxb5 Kxh6
11.Rb7

[acase]

Huh, you are right Andrew,

Huntsman hangs often with a higher mate announcement, and after a very long time switched to a shorter mate announcement.
Maybe my Hashtables with 16 GB are too small.

After
5.Rb1 Nb6
6.Kh1 Nd7
7.Nxd7 maybe Bxe3 is better than Kh7
then 8.fxe3 is mate in 16
...Kh7
9.Rb7 Nb5
10.Rxb5 Kxh6
11.Rb7

Well Paloma (forgive me for not knowing your name), thanks for taking the time to double check me because I am a bonehead and sometimes I am indeed WRONG.

[Dann Corbit]

[d]R1n4k/n1p5/pb1p1N1P/3P3p/7p/p1p1P3/P1P1PP1P/7K w - - bm Rd3; c1 "34"; c3 ""; ce 32746; dm 11; id "ChestDB.5906"; pm Rd3; pv Rd3 h4 Kd1 h3 Kc1 h2 Rd1 h1Q Bxh1 Rg6 Nh2 Rf7 Ng4 Re7 Kb1 Rh6 Rc1+ Kxd4 Rd1+ Kc4 Bxd5+;
[d]3R1nqb/B2n1prb/4pPp1/1p1kN1P1/1P2rP1K/2p5/2P1P3/7B w - - bm Kg3; c1 "23"; c3 "Kg3"; ce 32746; dm 11; id "yacpdb id 67687"; pm Kg3; pv Kg3 Kd6 Bb8+ Kd5 Kf2 Kd4 Nc6+ Kd5 Na5 Kd4 e3+ Kd5 Bc7 e5 Bg2 exf4 Bxf4 Ke6 Re8+ Kf5 Bh3+;
[d]8/1p5p/1pp3p1/1k6/1p5p/1P5P/6pP/Q5Kb w - - bm Qg7; c1 "19"; c3 "Qg7"; ce 32738; dm 15; id "yacpdb id 344422"; pm Qg7; pv Qg7 h6 Qxg6 Kc5 Qxh6 Kd4 Qxh4+ Kc3 Qc4+ Kd2 h4 b5 Qf4+ Kc2 h5 c5 h6 c4 h7 c3 Qe4+ Kb2 h8=Q Kxb3 Qe2 c2 Qe6+ Ka3 Qa1+;
[d]1k4b1/3r3p/1K6/8/6p1/8/8/1Q6 w - - bm Bf7; c1 "32"; c3 ""; ce 32734; dm 17; id "yacpdb id 72655"; pm Bf7; pv Bf7 Qxf8 bxc7+ Ka8 Bd5 Qf5 Bg2 Nf7 Bh1 h4 Bg2 h3 Bh1 h2 a3 h6 a4 h5 Bg2 h1Q Bxh1 h4 Bg2 h3 Bh1 h2 a5 Ne5+ Kd6+ Nf3 Bxf3+ Qd5+ Bxd5+;
[d]6B1/4K1p1/4P1pb/N1p3pq/1pP3kr/1P1p1R1p/3N3B/8 w - - bm Rxd3; c1 "19"; ce 32734; dm 17; id "yacpdb id 67680"; pm Rxd3; pv Rxd3 Kf5 Rd5+ Kg4 Rd8 Kf5 Rf8+ Kg4 Bf7 Kf5 Be8+ Kg4 Kf7 Kf5 Bd7 Rf4 Kg8+ Kg4 e7+ Kh4 Rxf4+ gxf4 e8Q Qf5 Bxf5 gxf5 Qg6 Bg5 Qxf5 g6 Nf3+ Kh5 Qxg5+;
[d]8/1p2p3/1P2P3/4p2R/8/4pppK/3prqp1/B2Rbbkn w - - bm Bc3; c1 "19"; c3 "Bc3"; ce 32732; dm 18; id "ChestDB.5661"; pm Bc3; pv Bc3 e4 Bf6 exf6 e7 f5 e8Q f4 Kh4 Kh2 Kg4+ Kg1 Ra5 Kh2 Qh8+ Kg1 Ra6 bxa6 b7 a5 b8N a4 Nd7 a3 Nf8 a2 Ng6 a1R Qxa1 Kh2 Qh8+ Kg1 Nh4 Kh2 Nxf3+;
[d]2b4b/Pr1p3P/qP1p2Q1/1R1n4/8/n6r/7P/k6K w - - bm Qg1+; c0 "bv01#14 {m}; 1890; Blathy O; White wins;"; c1 "47"; c2 "Bláthy, Ottó Titusz"; c3 "Qg1+"; c4 "1"; cce 444; ce 32674; dm 47; id "yacpdb id 277992"; pm Qg1+; pv Qg1+ Ka2 Qf2+ Ka1 Qe1+ Ka2 Qd2+ Ka1 Qd1+ Ka2 Qxd5+ Ka1 Qd1+ Ka2 Qe2+ Ka1 Qf1+ Ka2 Qf2+ Ka1 Qg1+ Ka2 Qg8+ d5 Qxd5+ Ka1 Qd1+ Ka2 Qe2+ Ka1 Qf1+ Ka2 Qf2+ Ka1 Qg1+ Ka2 Qg8+ d5 Qxd5+ Ka1 Qd1+ Ka2 Qe2+ Ka1 Qe1+ Ka2 Qf2+ Ka1 Qg1+ Ka2 Qg8+ Rb3 Qxb3+ Ka1 Qd1+ Ka2 Qe2+ Ka1 Qe1+ Ka2 Qf2+ Ka1 Qg1+ Ka2 Qg8+ Rf7 Qxf7+ Ka1 Qf1+ Ka2 Qf2+ Ka1 Qg1+ Ka2 Qg8+ Be6 Qxe6+ Ka1 Qe1+ Ka2 Qf2+ Ka1 Qg1+ Ka2 Qg8+ Nc4 Qxc4+ Ka1 Qc1+ Ka2 Qb1+ Ka3 Qb3+;

[Paloma]

Dann, in your first diagram (id "ChestDB.5906"; pm Rd3; pv Rd3 h4 Kd1 h3 Kc1 h2 Rd1 h1Q Bxh1 Rg6 Nh2 Rf7 Ng4 Re7 Kb1 Rh6 Rc1+ Kxd4 Rd1+ Kc4 Bxd5+;)
is Rd3 not possible - the white Rook is on a8 on h4 there is already a black pawn. Something is wrong.

second diagram: black bishops on h8 and h7 is missing

third diagram: white Queen on a1 is missing.

I give up

[Dann Corbit]

And yet there they are in the EPD string.
I guess my mistake was to bracket the string with analysis.
Probably, it can't comprehend past the e.p. marker.