Faster Forced Mate

Discussion of anything and everything relating to chess playing software and machines.

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Vinvin
Posts: 5228
Joined: Thu Mar 09, 2006 9:40 am
Full name: Vincent Lejeune

Re: Forced Mate #57 ChestUCI.epd position 6330

Post by Vinvin »

With no learning at all, Sting-SF 8.5 finds a mate in 65 in 47m11s (6*4GHz).
No more lines after 3 hours :?
FEN: 7n/ppp2p2/2N2Pp1/6B1/8/8/p1p2PKp/rbNk1rbR w - - 0 1

Code: Select all

Sting-sf-85:
...
 41	04:00	 2 145 295k	8 926k	 0,00	1.Kxf1 bxc6 2.Kg2 Ke1 3.Kf3 Kd1 4.Kg3 Ke1 5.Kg2 Kd1 6.Kf1 c5 7.Kg2 Ke1 8.Kg3 Kd1 9.Kh3 Ke1 10.Kg2 a6 11.Kf3 Kd1 12.Kg3 Ke1 13.Kg2 a5 14.Kg3 Kd1 15.Kf3 Ke1 16.Kg2 Kd1 17.Kg3 Ke1 18.Kg2
 42	06:04	 3 352 126k	9 185k	 0,00	1.Kxf1 bxc6 2.Kg2 Ke1 3.Kf3 Kd1 4.Kg3 Ke1 5.Kg2 Kd1 6.Kf1 c5 7.Kg2 Ke1 8.Kg3 Kd1 9.Kh3 Ke1 10.Kg2 a6 11.Kf3 Kd1 12.Kg3 a5 13.Kf3 Ke1 14.Ke3 Kd1 15.Ke4 Ke1 16.Kf3 Kf1 17.Kg3 c4 18.Kf3 Ke1 19.Kg2 Kd1 20.Kf1 c3 21.Kg2 Ke1 22.Kg3 Kf1 23.Kf3 Ke1 24.Ke3 Kd1 25.Ke4
 43+	06:08	 3 379 554k	9 180k	+0,08	1.Kxf1
 43	07:09	 3 946 678k	9 181k	 0,00	1.Kxf1 bxc6 2.Kg2 Ke1 3.Kf3 Kd1 4.Kg3 Ke1 5.Kg2 Kd1 6.Kf1 c5 7.Kg2 Ke1 8.Kg3 Kf1 9.Kf3 a6 10.Kg3 Ke1 11.Kg2 c4 12.Kf3 c6 13.Kg2 Kd1 14.Kf1 a5 15.Kg2 Ke1 16.Kf3 Kd1 17.Kg3 Ke1 18.Kg2 c5 19.Kf3 Kf1 20.Kg3 Ke1 21.Kg2 Kd1 22.Kf1 c3 23.Kg2 Ke1 24.Kg3 Kf1 25.Kf3 Ke1 26.Kg3
 44+	07:11	 3 958 462k	9 180k	+0,08	1.Kxf1
 44	10:26	 5 763 827k	9 207k	 0,00	1.Kxf1 bxc6 2.Kg2 Ke1 3.Kf3 Kd1 4.Kg3 Ke1 5.Kg2 Kd1
 45+	10:35	 5 846 244k	9 199k	+0,08	1.Kxf1
 45	15:01	 8 272 465k	9 176k	 0,00	1.Kxf1 bxc6 2.Kg2 Ke1 3.Kf3 Kd1 4.Kg3 Ke1 5.Kg2 Kd1 6.Kf1 c5 7.Kg2
 46+	15:31	 8 509 833k	9 134k	+0,08	1.Kxf1
 46+	15:33	 8 522 512k	9 130k	+0,16	1.Kxf1
 46	27:03	 14 751 657k	9 089k	 0,00	1.Kxf1 bxc6 2.Kg2 Ke1 3.Kf3 Kd1 4.Kg3 Ke1 5.Kg2 Kd1 6.Kf1 c5 7.Kg2 Ke1 8.Kf3 Kd1 9.Kg3 Ke1 10.Kg2 a6 11.Kf3 c4 12.Bf4 c6 13.Bxh2
 47+	27:08	 14 797 052k	9 087k	+0,08	1.Kxf1
 47+	27:10	 14 810 236k	9 086k	+0,16	1.Kxf1
 47+	39:19	 22 095 666k	9 363k	+4,04	1.Kxf1
 47	44:46	 25 085 257k	9 339k	+5,89	1.Kxf1 bxc6 2.Kg2 Ke1 3.Kf3 Kd1 4.Ke4 Ke1 5.Bf4 g5 6.Bxh2 Kd2 7.Rxg1 Ng6 8.Bxc7 Kc3 9.Rxg5 Nf8 10.Be5+ Kc4 11.Bxa1 Ne6 12.Rg4 a6 13.Ke3+ Kd5 14.Rg7 Nd8 15.Rg5+ Kd6 16.Ra5 Nb7 17.Rxa6 Kd5 18.Kd2 Nc5 19.Ra5 Kc4 20.Ra7 Ne4+ 21.Ke3 Nd6
 48+	45:40	 25 643 360k	9 359k	+6,02	1.Kxf1
 48+	46:11	 25 957 209k	9 367k	+6,14	1.Kxf1
 48+	47:11	 26 568 519k	9 384k	+M65	1.Kxf1
MikeGL
Posts: 1010
Joined: Thu Sep 01, 2011 2:49 pm

Re: Forced Mate #39 ChestUCI.epd position 6269

Post by MikeGL »

[d]8/5p1p/B2p1P2/p2P2NP/2rP3N/n5p1/3K1pP1/5kbn w - - 0 1
White to play, Mate in 39
/source ChestUCI.epd position 6269

Triangulation square: h4

[pgn]
[Event "Computer chess game"]
[Site "?"]
[Date "2017.07.07"]
[Round "?"]
[White "?"]
[Black "McBrain_2017"]
[Result "1-0"]
[TimeControl "0+2"]
[SetUp "1"]
[FEN "8/5p1p/B2p1P2/p2P2NP/2rP3N/n5p1/3K1pP1/5kbn w - - 0 1"]
[Termination "normal"]
[PlyCount "77"]
[WhiteType "human"]
[BlackType "human"]

1. Kd1 h6 2. Nh3 Bh2 3. Nf4 Kg1 4. Nf3+ Kf1 5. Kd2 Bg1 (5. .. Nb1+ 6. Kd3
{+M10 + -}) 6. Ke3 (6. Kd3? Rb4 7. Kd2+ Nb5 {=}) 6. .. Nc2+ 7. Ke4 Na3 8.
Kf5 Bh2 9. Kg4 Bg1 10. Kh3 Bh2 11. Kh4 Bg1 12. Kg4 Bh2 13. Kf5 Bg1 14. Ke4
Bh2 15. Ke3 Nc2+ 16. Kd2 Na3 17. Kd1 a4 18. Kd2 Bg1 19. Ke3 Bh2 20. Ke4 Bg1
21. Kf5 Bh2 22. Kg4 Bg1 23. Kh3 Bh2 24. Kh4 Bg1 25. Kg4 Bh2 26. Kf5 Bg1 27.
Ke4 Bh2 28. Ke3 Bg1 29. Kd2 Nb1+ 30. Kd3 Na3 31. Bxc4 Nxc4 32. Kxc4 Bh2 33.
Kb4 a3 34. Kxa3 Bg1 35. Kb4 Bh2 36. Kc3 Bg1 37. Kd2 Bh2 38. Kd1 Bg1 39.
Nd2# 1-0
[/pgn]

Solution not found elsewhere.

regards
MikeGL
Posts: 1010
Joined: Thu Sep 01, 2011 2:49 pm

Re: Mate in 55 ChestUCI.epd position 6325

Post by MikeGL »

yacpdb position: 302976
ChestUCI.epd position:6325

[d]rrk1N2N/pRn3p1/PbBp1pp1/3P4/K1pP3n/2p5/2P3p1/6Bb w - - 0 1

White to Play, Mate in #55
Possible solution follows:

[pgn]
[Event "Computer chess game"]
[Site "Talkchess"]
[Date "2017.07.13"]
[Round "?"]
[White "?"]
[Black "McBrain_2017"]
[Result "1-0"]
[TimeControl "60"]
[SetUp "1"]
[FEN "rrk1N2N/pRn3p1/PbBp1pp1/3P4/K1pP3n/2p5/2P3p1/6Bb w - - 0 1"]
[Termination "normal"]
[PlyCount "109"]
[WhiteType "human"]
[BlackType "human"]

1. Nf7 Nf5 2. Ka3 Ba5 3. Ka2 Bb6 4. Kb1 Ba5 5. Ka1 Bb6 6. Ka2 Ba5 7. Ka3
Bb6 8. Ka4 g5 9. Ka3 Ba5 10. Ka2 Bb6 11. Kb1 Ba5 12. Ka1 Bb6 13. Ka2 Ba5
14. Ka3 Bb6 15. Ka4 g4 16. Ka3 Ba5 17. Ka2 Bb6 18. Kb1 Ba5 19. Ka1 Bb6 20.
Ka2 Ba5 21. Ka3 Bb6 22. Ka4 g6 23. Ka3 Ba5 24. Ka2 Bb6 25. Kb1 Ba5 26. Ka1
Bb6 27. Ka2 Ba5 28. Ka3 Bb6 29. Ka4 g5 30. Ka3 Ba5 31. Ka2 Bb6 32. Kb1 (32.
Ka1? Ba5 33. Kb1? Nxa6=) 32. .. Ba5 33. Ka1 Bb6 34. Ka2 Ba5 35. Ka3 Bb6 36.
Ka4 g3 37. Ka3 Ba5 38. Ka2 Bb6 39. Kb1 Ba5 40. Ka1 Bb6 41. Ka2 Ba5 42. Ka3
Bb6 43. Ka4 g4 44. Ka3 Ba5 45. Ka2 Bb6 46. Kb1 Ba5 47. Ka1 Bb6 48. Ka2 Ba5
49. Ka3 Bb6 50. Ka4 Ba5 51. Kxa5 Rxb7 52. axb7+ Kb8 53. Nxc7 Kxc7 54.
bxa8=Q a6 55. Qb7# 1-0
[/pgn]

triangulate: Ka2 > Kb1 > Ka1
Solution not found elsewhere.



regards
MikeGL
Posts: 1010
Joined: Thu Sep 01, 2011 2:49 pm

Re: Mate in 55 ChestUCI.epd position 6325

Post by MikeGL »

MikeGL wrote:yacpdb position: 302976
ChestUCI.epd position:6325

[d]rrk1N2N/pRn3p1/PbBp1pp1/3P4/K1pP3n/2p5/2P3p1/6Bb w - - 0 1

White to Play, Mate in #55
Possible solution follows:

[pgn]
[Event "Computer chess game"]
[Site "Talkchess"]
[Date "2017.07.13"]
[Round "?"]
[White "?"]
[Black "McBrain_2017"]
[Result "1-0"]
[TimeControl "60"]
[SetUp "1"]
[FEN "rrk1N2N/pRn3p1/PbBp1pp1/3P4/K1pP3n/2p5/2P3p1/6Bb w - - 0 1"]
[Termination "normal"]
[PlyCount "109"]
[WhiteType "human"]
[BlackType "human"]

1. Nf7 Nf5 2. Ka3 Ba5 3. Ka2 Bb6 4. Kb1 Ba5 5. Ka1 Bb6 6. Ka2 Ba5 7. Ka3
Bb6 8. Ka4 g5 9. Ka3 Ba5 10. Ka2 Bb6 11. Kb1 Ba5 12. Ka1 Bb6 13. Ka2 Ba5
14. Ka3 Bb6 15. Ka4 g4 16. Ka3 Ba5 17. Ka2 Bb6 18. Kb1 Ba5 19. Ka1 Bb6 20.
Ka2 Ba5 21. Ka3 Bb6 22. Ka4 g6 23. Ka3 Ba5 24. Ka2 Bb6 25. Kb1 Ba5 26. Ka1
Bb6 27. Ka2 Ba5 28. Ka3 Bb6 29. Ka4 g5 30. Ka3 Ba5 31. Ka2 Bb6 32. Kb1 (32.
Ka1? Ba5 33. Kb1? Nxa6=) 32. .. Ba5 33. Ka1 Bb6 34. Ka2 Ba5 35. Ka3 Bb6 36.
Ka4 g3 37. Ka3 Ba5 38. Ka2 Bb6 39. Kb1 Ba5 40. Ka1 Bb6 41. Ka2 Ba5 42. Ka3
Bb6 43. Ka4 g4 44. Ka3 Ba5 45. Ka2 Bb6 46. Kb1 Ba5 47. Ka1 Bb6 48. Ka2 Ba5
49. Ka3 Bb6 50. Ka4 Ba5 51. Kxa5 Rxb7 52. axb7+ Kb8 53. Nxc7 Kxc7 54.
bxa8=Q a6 55. Qb7# 1-0
[/pgn]

triangulate: Ka2 > Kb1 > Ka1
Solution not found elsewhere.



regards
There are clues from engines that a possible cook is lurking on this puzzle.
Similar to this case pointed out by Vincent in previous page.

The possible cook on above position starts with 1.Nxd6+ Δ 2.Ndf7+ Δ 3.d6+! Δ 4.dxc7 which
seems to deliver a faster mate. Maybe this will be apparent once
engines and hardwares are fast enough to confirm there's a faster mate than 55 moves.

regards
peter
Posts: 3186
Joined: Sat Feb 16, 2008 7:38 am
Full name: Peter Martan

Re: Mate in 55 ChestUCI.epd position 6325

Post by peter »

MikeGL wrote: ...
[d]rrk1N2N/pRn3p1/PbBp1pp1/3P4/K1pP3n/2p5/2P3p1/6Bb w - - 0 1
...
The possible cook on above position starts with 1.Nxd6+ Δ 2.Ndf7+ Δ 3.d6+! Δ 4.dxc7 which
seems to deliver a faster mate.
what's the continuation of your line, Milan? After setting the black King free, how to deliver mate then
:?:
Peter.
peter
Posts: 3186
Joined: Sat Feb 16, 2008 7:38 am
Full name: Peter Martan

Re: Mate in 55 ChestUCI.epd position 6325

Post by peter »

Sorry for typing Milan instead of Mike, Mike, no more time to edit
:oops:
BTW best engine by far for backwarding this it good old Zappa with Mate Extensions on and Nullmove off:

rrk1N2N/pRn3p1/PbBp1pp1/3P4/K1pP3n/2p5/2P3p1/6Bb w - - 0 1

Analysis by Zappa Mexico II x64:

1.Nf7 Nf5 2.Ka3 Ba5 3.Ka2 Bb6 4.Kb1 Ba5 5.Ka1 Bb6 6.Ka2 Ba5 7.Ka3 Bb6 8.Ka4 g5 9.Ka3 Ba5 10.Ka2 Bb6 11.Kb1 Ba5 12.Ka1 Bb6 13.Ka2 Ba5 14.Ka3 Bb6 15.Ka4 g6 16.Ka3 Ba5 17.Ka2 Bb6
+- (#55) Depth: 16/49 00:00:08 95385kN
Peter.
MikeGL
Posts: 1010
Joined: Thu Sep 01, 2011 2:49 pm

COOK? Re: Mate in 55 ChestUCI.epd position 6325

Post by MikeGL »

peter wrote:Sorry for typing Milan instead of Mike, Mike, no more time to edit
:oops:
BTW best engine by far for backwarding this it good old Zappa with Mate Extensions on and Nullmove off:

rrk1N2N/pRn3p1/PbBp1pp1/3P4/K1pP3n/2p5/2P3p1/6Bb w - - 0 1

Analysis by Zappa Mexico II x64:

1.Nf7 Nf5 2.Ka3 Ba5 3.Ka2 Bb6 4.Kb1 Ba5 5.Ka1 Bb6 6.Ka2 Ba5 7.Ka3 Bb6 8.Ka4 g5 9.Ka3 Ba5 10.Ka2 Bb6 11.Kb1 Ba5 12.Ka1 Bb6 13.Ka2 Ba5 14.Ka3 Bb6 15.Ka4 g6 16.Ka3 Ba5 17.Ka2 Bb6
+- (#55) Depth: 16/49 00:00:08 95385kN
I like the name Milan, perhaps his parents went for a honeymoon there?:lol:

On a serious note, I have tried to analyze and played out a possible continuation with engine assistance:

Here's the possible cook line for the above puzzle
[pgn]
[Event "Computer chess game"]
[Site "Talkchess"]
[Date "2017.07.25"]
[Round "?"]
[White "McBrain_2017"]
[Black "McBrain_2017"]
[Result "?"]
[BlackElo "2400"]
[SetUp "1"]
[FEN "rrk1N2N/pRn3p1/PbBp1pp1/3P4/K1pP3n/2p5/2P3p1/6Bb w - - 0 1"]
[Termination "unterminated"]
[PlyCount "35"]
[WhiteType "human"]
[BlackType "human"]

1. Nxd6+ Kd8 2. Ndf7+ Ke7 3. d6+ Kf8 4. dxc7 Bxc7 5. Rxc7 Rb1 6. Bxa8 Rxg1
7. Bc6 Ra1+ 8. Kb5 Rb1+ (8. .. g1=Q 9. Rc8+ Ke7 10. Re8#) 9. Kc5 Kg8 10.
Ng5 Rb8 (10. .. fxg5 11. Rc8+ Kh7 12. Nf7 { Rh8#}) 11. Nh3 g5 12. Rxa7 g4
13. Ng1 Rb1 14. Be4 (14. Ra8+ Kh7 15. Nf7 Rxg1 16. Rh8+ Kg6 17. Rxh4 Kxf7
{unclear}) 14. .. f5 15. Nf7 fxe4 16. Ng5 g6 17. Ra8+ Kg7 18. Ne6+ {1-0}
[/pgn]

After this line, I am not sure if white can deliver checkmate in less than 37
moves. If it could then this is a cook. But this possible continuation is a
fighting game and very difficult to continue because of complications and
would require further investigation. But maybe your Zappa x64 analysis just
confirmed that the triangulation, common to Bláthy problem, is the
correct approach.

regards
peter
Posts: 3186
Joined: Sat Feb 16, 2008 7:38 am
Full name: Peter Martan

Re: COOK? Re: Mate in 55 ChestUCI.epd position 6325

Post by peter »

MikeGL wrote:
Here's the possible cook line for the above puzzle
[pgn]
[Event "Computer chess game"]
[Site "Talkchess"]
[Date "2017.07.25"]
[Round "?"]
[White "McBrain_2017"]
[Black "McBrain_2017"]
[Result "?"]
[BlackElo "2400"]
[SetUp "1"]
[FEN "rrk1N2N/pRn3p1/PbBp1pp1/3P4/K1pP3n/2p5/2P3p1/6Bb w - - 0 1"]
[Termination "unterminated"]
[PlyCount "35"]
[WhiteType "human"]
[BlackType "human"]

1. Nxd6+ Kd8 2. Ndf7+ Ke7 3. d6+ Kf8 4. dxc7 Bxc7 5. Rxc7 Rb1 6. Bxa8 Rxg1
7. Bc6 Ra1+ 8. Kb5 Rb1+ (8. .. g1=Q 9. Rc8+ Ke7 10. Re8#) 9. Kc5 Kg8 10.
Ng5 Rb8 (10. .. fxg5 11. Rc8+ Kh7 12. Nf7 { Rh8#}) 11. Nh3 g5 12. Rxa7 g4
13. Ng1 Rb1 14. Be4 (14. Ra8+ Kh7 15. Nf7 Rxg1 16. Rh8+ Kg6 17. Rxh4 Kxf7
{unclear}) 14. .. f5 15. Nf7 fxe4 16. Ng5 g6 17. Ra8+ Kg7 18. Ne6+ {1-0}
[/pgn]
At the end of your line I think Black gets mated at about 65th to70th maybe.

But how about not taking the Bishop sac at 15th, what's your line after 15...Kh7

rrk1N2N/pRn3p1/PbBp1pp1/3P4/K1pP3n/2p5/2P3p1/6Bb w - - 0 1

1. Nxd6+ Kd8 2. Ndf7+ Ke7 3. d6+ Kf8 4. dxc7 Bxc7 5. Rxc7 Rb1 6. Bxa8 Rxg1 7.Bc6 Ra1+ 8. Kb5 Rb1+ 9. Kc5 Kg8 10. Ng5 Rb8 11. Nh3 g5 12. Rxa7 g4 13. Ng1 Rb1 14. Be4 f5 15. Nf7 Kh7

:

[d]8/R4Npk/P7/2K2p2/2pPB1pn/2p5/2P3p1/1r4Nb w - - 0 16

:?:
Peter.
MikeGL
Posts: 1010
Joined: Thu Sep 01, 2011 2:49 pm

Re: Re: Mate in 55 ChestUCI.epd position 6325

Post by MikeGL »

15. .. Kh7 16. Ng5+ Kg6 17. Rxg7+ Kxg7 18. a7 Ra1 19. a8=Q Rxa8 20. Bxa8 =

You could be correct,
Position looks unclear but engines scores it as roughly equal. After this 20th move, only 35 moves left for the cook but even a win is impossible let alone a Mate in 35.


regards
peter
Posts: 3186
Joined: Sat Feb 16, 2008 7:38 am
Full name: Peter Martan

Re: COOK? Re: Mate in 55 ChestUCI.epd position 6325

Post by peter »

peter wrote:But how about not taking the Bishop sac at 15th, what's your line after 15...Kh7

rrk1N2N/pRn3p1/PbBp1pp1/3P4/K1pP3n/2p5/2P3p1/6Bb w - - 0 1

1. Nxd6+ Kd8 2. Ndf7+ Ke7 3. d6+ Kf8 4. dxc7 Bxc7 5. Rxc7 Rb1 6. Bxa8 Rxg1 7.Bc6 Ra1+ 8. Kb5 Rb1+ 9. Kc5 Kg8 10. Ng5 Rb8 11. Nh3 g5 12. Rxa7 g4 13. Ng1 Rb1 14. Be4 f5 15. Nf7 Kh7

:

[d]8/R4Npk/P7/2K2p2/2pPB1pn/2p5/2P3p1/1r4Nb w - - 0 16

:?:
As far as I can see, there are only two not losing moves for White here, both leading to more or less forced draw:

[pgn]
[Event "#55 Classic Triangle"]
[Site "?"]
[Date "2017.07.25"]
[Round "?"]
[White "Krzek, Janusz"]
[Black "Phénix, 1993"]
[Result "1-0"]
[Annotator "Martan,Peter"]
[SetUp "1"]
[FEN "rrk1N2N/pRn3p1/PbBp1pp1/3P4/K1pP3n/2p5/2P3p1/6Bb w - - 0 1"]
[PlyCount "50"]

1. Nxd6+ $2 (1. Nf7 $1 {#55}) 1... Kd8 2. Ndf7+ Ke7 3. d6+ Kf8 4. dxc7 Bxc7 5.
Rxc7 Rb1 6. Bxa8 Rxg1 7. Bc6 Ra1+ 8. Kb5 Rb1+ 9. Kc5 Kg8 10. Ng5 Rb8 11. Nh3 g5
12. Rxa7 g4 13. Ng1 Rb1 14. Be4 f5 15. Nf7 Kh7 (15... fxe4 $2 16. Ng5 g6 17.
Ra8+ Kg7 18. Ne6+ Kf6 19. a7 Ra1 20. Kd6 Rxa7 21. Rxa7 Nf5+ 22. Kd7 e3 23. Ra8
g5 24. d5 e2 25. Nxe2 g1=B 26. Nxg1 Bxd5 27. Ra6 Ne3 28. Ne2 Ke5 29. Ra5 Kf6
30. N6d4 Ke5 31. Nb5 Be6+ 32. Kc6 Bd5+ 33. Kc7 Bf3 34. Nbxc3+ Kf6 35. Nd4 Kg6
36. Kd6 Kh5 37. Ke7 Kg6 38. Re5 Nf1 39. Re6+ Kh5 40. Kf6 Nd2 41. Re5 Kh4 42.
Rxg5 Kg3 43. Kf5 Nf1 44. Ne4+ Kg2 45. Kf4 Bxe4 46. Kxe4 g3 47. Nf5 Kf2 48. Nxg3
Nxg3+ 49. Rxg3 Kxg3 50. Kd4 c3 51. Kxc3 Kg4 52. Kd4 Kf5 53. Kd5 Kf6 54. Kd6 Kg7
55. c4 Kf8 56. Kd7 Kg7 57. c5 Kf6 58. c6 Ke5 59. c7 Kd4 60. c8=Q Ke3 61. Kc6
Kf4 62. Kd5 Kf3 63. Qf5+ Kg2 64. Qg4+ Kf2 65. Ke4 Ke1 66. Qg2 Kd1 67. Kd3 Kc1
68. Qc2#) 16. Ng5+ (16. Bxg2 Bxg2 17. Ne2 Rb2 18. d5 Rxc2 19. Re7 Ng6 20. Re6
Bxd5 21. Ng5+ Kh6 22. Nf7+ Kh7 23. Ng5+ Kh6 24. Nf7+ Kh7 {3f}) (16. Ne2 $2 fxe4
$19) 16... Kg6 17. Rxg7+ Kxg7 18. a7 Ra1 19. a8=Q Rxa8 20. Bxa8 Kf6 $11 21. d5
Ng6 22. Nh7+ Kg7 23. Ng5 Kf6 24. Nh7+ Kg7 25. Ng5 Kf6 {3f} 1-0
[/pgn]
Peter.