Friday, 15 June 2018

Syzygy Endgame Explorer (SEE)

Syzygy Endgame Explorer (SEE) is a software written by me for mining the newly generated 7-man endgame tablebases. In my previous post, I've presented the first study based on this mutual zugzwang found by SEE:

The tool can not only find mutual zugzwangs but can also identify positions where interesting moves are the only winning ones (like when a piece moves to a corner square or it is sacrificed). The software is still in the very early phases of development but my goal is to write a tool similar to CQL which searches tablebases instead of pgn files.

For example, this is a position found by SEE:

The only winning move for white is a surprising move to the corner square: 1.Ka1! (tempo). Black is in zugzwang, although not a mutual one. White could reverse its key by moving back to b2.

Making a full search in the tablebase is very time-consuming. Instead, I did searches by adding some constraints to the position of pieces. The following mutual zugzwang was found by restricting the knights to the long diagonal. It is interesting to see how two knights are immobilised in opposite corners:

The next position is a mutual zugzwang unless black has still kept the right to castle! If black can still castle, it saves the draw by 1...0-0! This position was found by restricting the black king to e8 and the black rook to h8.

Study 151

Árpád Rusz
Internet (RCS blog)
2018

White wins

The stipulation seems wrong: shouldn't white only fight for a draw?
1. Ba5+ Kc8 1... Kd7 2. Nf6+ +- 2. Nc5! 2. Nf6? Qg7 3. Bf3 Qc7! 4. Bg4+ Kd8 = 2... Qg7 3. Bf3! Thematic try: 3. Be4? Qf7 4. Bg2 Qh7 5. Bf3 Qg7 mutual zugzwang 6. Be4 Qf7 positional draw


mutual zugzwang

Now the black queen cannot move: it has to keep an eye on both the b7 and g4 squares (Focal Theme). The knight moves lead also to a disaster:

a. 3... Nf7 4. Bb7#
b. 3... Ng6 4. Bg4+ +-

Watch this study on a dynamic board! Click here!

This study features one of the first mutual zugzwangs found by Syzygy Endgame Explorer (SEE). More details in the next post.

Friday, 1 June 2018

Study 150

Árpád Rusz
Jirtdan Ty
2018
Special Commendation

White wins

1. d4 Nf3 1... Ne2 2. d5 Nc3 3. d6! Nxa4 4. d7 +- 2. d5 Ne5 2... Nd4 3. Kf6 +- 3. d6 3. Ke6? Nc4 = 3... Kg5 In order to win, white has to reach the same position but with black to move.


cyclic zugzwang - WTM

4. Ke6 Nd3 5. Bb5 5. d7? Nc5+ =; 5. Bc2? Nc5+ 6. Kd5 Nd7 = 5... Nf4+ 6. Kf7! Thematic try: It is too early for 6. Kd7?! (Position X') 6... Ng6 7. Bd3? Ne5+ 8. Ke6 Nxd3 9. d7 Nc5+ = 6... Ng6 7. Ba4! 7. d7? Ne5+ =; 7. Bc6? Ne5+ = 7... Ne5+ 7... Kf5 8. Bc2+ +- 8. Ke7! White has managed to transfer the move to black. While the white king made a triangle manoeuvre (Ke7-e6-f7-e7, 3 moves) and the bishop a switchback (Ba4-b5-a4, 2 moves), the black knight walked on a diamond-shaped path (Ne5-d3-f4-g6-e5, 4 moves). These manoeuvres result in a tempo loss by white.


cyclic zugzwang - BTM

8... Ng6+ 8... Kf4 9. Kf6! (9. Ke6? Nd3 positional draw 10. Kd5 Ne5 11. Ke6 Nd3 positional draw) 9... Ke4 10. Ke6 Nd3 11. Bc2 +- pin 9. Ke6 Nf4+

10. Kd7! (Position X) 10... Kf6 10... Ng6 11. Bc2 Ne5+ 12. Ke6 +- Now d3 is not available for the knight. Please, compare it with the thematic try. 11. Kc8! Nd5 12. Bb3! 12. d7? Nb6+ = 12... Ke5! 12... Ke6 13. d7+- pin 13. Kd7! Switchback 13... Nf6+ 14. Ke7 Kf5 15. Ba2(c4,f7) tempo 15... Ke5 16. Be6 +-

Watch this study on a dynamic board! Click here!

Related study: Study 73

Thursday, 17 May 2018

Study 149

Árpád Rusz
Problemist of Ukraine
2018

Draw

We have a symmetric initial position, so why shouldn't the only key move also be symmetric? It seems so natural to push the passed pawn... 1. d7? Kd1!! 1... Rc3? 2. Re8 Rd3+ 3. Kc6 =; 1... Re3? 2. Rc8 Rd3+ 3. Ke6 = 2. Rc8 2. Re8 Red2+ 3. Ke6 Rc6+ 4. Ke7 Rc7 -+ 2... Rcd2+ 3. Kc6 Re6+ 4. Kc7 Re7 -+

So the key should be a rook move. But where to place the rook?

Thematic try: 1. Rh8? Rc3 2. Rh4 Re8 3. Rd4+ Ke3 4. Rd1 Ke2 5. Rd4 Rd8 6. Ke6 Re3+ 7. Kf7 Rd7+ 8. Kf6 Now both black's king and one of its rooks are on the longer flank where there is more space to manoeuvre.

8... Re8 This is the quickest win. 9. Rd5 Re4 10. Kf5 Rh4! -+

The real key is a surprising move to the other corner:
1. Ra8!! After the rook was oddly placed in front of the passed pawn, now white seems to break another principle: "In rook endgames, it is usually better to choose the longer flank." 1... Re3 1... Rc3 2. Ra2+ = 2. Ra4! 2. d7? Rd3+ 3. Ke6 Rc6+ 4. Ke7 Rc7 -+ 2... Rc8 2... Rd3+ 3. Rd4 = 3. Rd4+ Kc3 4. Rd1! White has managed to transfer the rook behind its passed pawn! 4. d7? Rd8 -+ 4... Kc2 5. Rd4 Rd8 5... Kc3 6. Rd1 positional draw 6. Kc6 Rc3+ 7. Kb7 7. Kb6? Rb8+ -+ 7... Rd7+ 8. Kb6 Now both black's king and one of its rooks are on the shorter flank where there is less space to manoeuvre.

8... Rc8 9. Rd5 Rc4 10. Kb5 Now black doesn't have a move like 10. ..Rh4! from the thematic try! 10... Rc3 11. Kb6 Ra3! 12. Rd4! 12. Kc6? Rda7! 13. d7 R3a6+ 14. Kc5 Ra5+ 15. Kd4 Rxd5+ 16. Kxd5 Rxd7+ -+ 12... Kc3 13. Rd1 Kc4 14. Kc6 Rda7 15. Rc1+ Pushing the pawn would be fatal: 15. d7? R3a6# 15... Kb4 16. Rb1+ Ka5 16... Kc4 17. Rc1+ perpetual check 17. Rb5+ 17. d7? Rc3+ 18. Kd6 Rd3+ -+ 17... Ka6 17... Ka4 18. Rd5 = 18. Rb6+ Ka5 19. Rb5+ perpetual check

Watch this study on a dynamic board! Click here!

Monday, 14 May 2018

Study 148

Árpád Rusz
Variantim
2017

White wins

1. Ra8+!
a. 1... Rb8 2. Rc8+! 2. Rxb8+? Qxb8 3. Qxd7 Qf4+ 4. Kg6 Qg5+! 5. Kf7 Qh5+! 6. Kf8 Qh6+ = 2... Rd8 3. Qe8+!! Qf8+


Domino Theme

Now the pieces will start to fall one by one like some dominoes. Maybe this new theme should be called the "Domino Theme". 4. Qxf8+ Rxf8 5. Rxf8+ Rxf8 6. Rxf8#

b. 1... Rd8 2. Rxd8+ Qxd8 3. Qxb5 Qd2+ fork 3... Qf8+ 4. Kh5 +- 4. Kg6 Qg2+ The white rook was taboo. 5. Kf7! The pawn is also untouchable! 5. Kxf6? Qg7+ 6. Kf5 Qh7+ 7. Kg4 Qe4+ = 5... Qg8+ 6. Ke7! Qh7+ 7. Kd6! 7. Ke6? Qh3+ 8. Kd6 h1=Q 9. Qe8+ Kg7 (9... Kh7? 10. Qf7+ Kh8 11. Qxf6+ Kh7 12. Rc7+ +-) 10. Rc7+ Kh6 = 7... h1=Q 8. Qe8+ Kg7 9. Qd7+! 9. Rc7+? Kh6 10. Qe3+ Kg6 11. Qg3+ Kh6 = 9... Kh8 10. Qc8+! 10. Rc8+? Qg8 = 10... Kg7 11. Qg4+ Kf8 11... Kh6 12. Rxh1#; 11... Kh8 12. Rc8+ +- 12. Rc8+ Kf7 13. Rc7+ Kf8 14. Qc8#

Watch this study on a dynamic board! Click here!

Saturday, 12 May 2018

Polgar Starchess Endgame Studies

Invented by László Polgár, father of the famous Polgár sisters, Starchess is played on a star-shaped board with rules which are very similar to those from classical chess. This chess variant seems very suitable for endgame study composition.

-1-
Árpád Rusz
Internet
2009

Thematic try:

The end position is the following mutual zugzwang:

In the solution, the white king triangulates trying to reach the same position but with BTM. In order to find the correct first move, one has to see the final mutual zugzwang! These kind of long triangulations are very rare even in chess studies.

During solution, two dead white pawns are coming back to life. This theme is impossible in chess.

-2-
Árpád Rusz
Internet
2009

The white knight and the black king follow these paths during solution:

Black avoids two echo stalemates by echo promotions to bishop!

Tuesday, 8 May 2018

Study 147

Árpád Rusz
6th FIDE World Cup
2017
2nd Prize

White wins

Thematic try: 1. Nd3? Nf4! 2. Nc5+ 2. Nxf4+ Ke5 = 2... Kd6 3. Nd7 Ne6 4. e5+ Kd5 5. Kf7! Nc5 6. Ng4! Nxd7 7. e6 Nb6 8. Ne3+ 8. e7 Nc8 9. e8=Q Nd6+ = 8... Kc5 9. Ke7! Nc8+ 10. Kd7 Nb6+ 11. Kd8


Position X'

In this position, black has a saving manoeuvre! 11... Nc8! 12. Nc4! 12. Kxc8 Kd6 = 12... Na7!! Black uses the extra file on the longer flank! 12... Kd5? 13. Kd7 +- 13. Na5 13. e7 Nc6+ = 13... Nc8! 14. Nc4 Na7 15. Ne5 Nc8! 16. Nc4 Na7 positional draw

1. Nf3! Nd4! 1... Ng3 2. e5 Nf5 3. Nd3 Nd6+ 4. Kf8 +- 2. Ng5+ 2. Nxd4+? Ke5 = 2... Kf6 3. Nf7 Ne6 4. e5+ Kf5 5. Kd7! 5. Ke7? Ng5 6. Nc4 Nf3 = 5... Ng5 6. Nc4! 6.Nxg5? Kxe5 = 6... Nxf7 7. e6 Nh6 By sacrificing its h2 knight white had managed to keep the black knight on the shorter flank. 7... Kf6 8. e7 +- 8. Ne3+! 8. e7? Ng8 9. e8=Q Nf6+ = 8... Kg5 9. Ke7! Ng8+ 9... Kf4 10. Kf8! +- 10. Kf7 10. Kf8? Kf6! = 10... Nh6+ 11. Kf8 +-


Position X

In the thematic try we saw a mirrored position (Position X') but now black doesn't have a saving manoeuvre which starts with a knight sacrifice. There is no extra file next to the h-file!

Watch this study on a dynamic board! Click here!

Friday, 27 April 2018

Study 146

Árpád Rusz
Zinchuk-80 MT
2018
1st-2nd Prize

White wins

1. Rh2+ (1. c6? Ng3 2. c7 Rc4+ 3. Rc2 Ne2+ 4. Kd2 Nc3 =) 1... Kg3 2. Rd2! (2. Rxh1? Rc4+ =) 2... Rc4+! (2... Rxd2 3. Kxd2 Nf2 4. Bd5! (4. Bh1? Nxh1 5. c6 Nf2 6. c7 Ne4+ 7. Kd3 Nd6 =) 4... Ng4 5. c6 Nf6 6. c7 +-) 3. Rc2 Rxc2+ 4. Kxc2 Nf2 The knight has managed to escape from the corner square. Unfortunately, the g3 square was blocked by the king so the knight had to choose the inferior f2 square.

5. Bh1!! Umnov Theme. The bishop moves to a square just left by the knight. (5. Bd5? Ng4 6. c6 Ne3+ 7. Kb3 Nxd5 =; 5. c6? Ne4 6. c7 Nd6 =) 5... b3+! (5... Nxh1 6. c6 Nf2 7. c7 Ne4 8. c8=Q +-) 6. Kxb3 (6. Kb2? Nd3+ =; 6. Kb1? Nd1! 7. c6 Nc3+ 8. Kb2 Nb5 =) 6... Nd3 7. c6 Nc5+ 8. Kc4 Ne6 9. Kd5 Nc7+ 10. Kc5! (10. Kd6? Na8! 11. Kd7 Nb6+ 12. Kd6 (12. Kc7 Nc4 =) 12... Na8 positional draw) 10... Na8! Compared to the initial position, the knight and the bishop have interchanged their places.

11. Kb5 Kf4 12. Ka6 Ke5 (12... Nc7+ 13. Kb6 Ne8 14. Bd5 Ke5 15. Bf7 Nd6 16. c7! +-) 13. Kb7 Kd6

14. Kxa8 +- Who would have thought that the knight will be captured not on h1 but on the opposite corner square?

Watch this study on a dynamic board! Click here!

Related study: Study 122

Tuesday, 3 April 2018

Study 145

Árpád Rusz
Problem Paradise
2017

White wins

1. Bxf3! Rxg5! 1... Rxf3 2. g6 Rf1+ 3. Ka2 Rf8 4. g7 Ra8+ 5. Kb3! echo 5... Kd3 6. Kb4 Rb8+ 7. Ka5 Kc4 8. Be5 Re8 9. Kb6! +- (9. Bd6? Rg8 10. Bf8 Rxg7! 11. Bxg7 Kxc5 =) 2. c6 Ke3

3. Bh1! Rg1+ 4. Kc2!! echo 4. Ka2? Rxh1 5. c7 Rc1 =; 4. Kb2? Rxh1 5. c7 Rh8 = 4... Rxa1 4... Rxh1 5. c7 chameleon echo 5... Rh8 6. Bxh8 +- 5. c7 chameleon echo 5... Ra8 6. Bxa8 +-

Watch this study on a dynamic board! Click here!

Thursday, 18 January 2018

Study 144

Árpád Rusz
The Problemist
2018

Draw

1. Bxd7! 1. Nc5+? Kd5 2. Nxd7 Nxd6 3. Nf6+ Kc5! 4. Nd7+ Bxd7 5. Bxd7 Position X' 5... d3 -+ 1... Bxd7 2. Nc5+ The knight leaves the b3 square, but it will return there after a long trip. 2... Kd5 3. Nxd7 Nxd6 3... Kxd6 4. Nb6 d3 5. Nc4+ Kc5 6. Nd2 = 4. Nf6+! 4. Nb6+? Kc6 -+ 4... Ke6 4... Kc5 5. Nd7+ Position X - The knight proves to be more efficient than the bishop in the fight against the passed pawn. 5... Kd5 (5... Kc6 6. Ne5+ Kd5 7. Nd3 =) 6. Nf6+ Kc5 (6... Kc4 7. Ng4 d3 8. Ne5+ =) 7. Nd7+ perpetual check 5. Nh5! This extra file was missing from the other flank. 5... Kf5 5... d3 6. Nf4+ = 6. Ng3+ Kg4 7. Nf1! The knight has to stop the pawn before it reaches d2. 7. Ne2? d3 8. Nc3 d2 -+ 7... Kf3 8. Nd2+ Ke2 9. Nb3! = During the trip, the knight drew a big square on the board!

Watch this study on a dynamic board! Click here!

Tuesday, 16 January 2018

Study 143

Árpád Rusz
Joiţa MT
2018

White wins

The a4 pawn prevents a simple win (1.Rf4 followed by 2.Ra4#). In order to win, white will try to reach the same position but without the a4 pawn. But how does the "disappearing pawn magic trick" work?

1. Bf3! Logical try: 1. Rf4? Rd6! -+; 1. f3? Rf1! = 1... Rd4 1... Bxf3 2. Rxf3


Saavedra's double attack (echo)

2... Rh1 3. Ra3#; 1... Rd6 2. Rxd6 Bf5+ 3. Rd3! +- 2. Kc3! 2. Bxg4? Rxg4 3. Rxh6 Rg8 4. Ra6 Ra8 = 2... Rxa4 3. Kb3 Bd7! 3... Rd4 4. Bxg4 Rxg4 5. Rc6 Kb1 6. Rxc7 +- 4. Bc6! Rd4 4... Bxc6 5. Rxc6


Saavedra's double attack (echo)

5... Rxa5 6. Rc1# 5. Kc3! 5. Bxd7? Rxd7 6. Rxh6 Rd8 = 5... Rd1 6. Kc2 Bg4 We are back to the initial position but the a4 pawn has disappeared! 6... Rd4 7. Bxd7 Rxd7 8. Rf4! +-


The a4 pawn has disappeared!

7. Rf4! Rd6 8. Ra4#

Watch this study on a dynamic board! Click here!

Related study: Saavedra 1

Friday, 5 January 2018

Study 142

Árpád Rusz
Krug-50 JT
2017
1st Special Prize
- after Bourzutschky & Konoval -

White wins

Try: 1. Rc6+? Kd7 In the following two variations black saves the game by sacrificing the knight or the rook. This provides some comfort for the fact that in the actual mainline these two black pieces are captured on their initial squares. 1... Ke7? 2. Ne3! knight sacrifice 2... Nxe3 3. Kxf4 +- 2. Rc5 2. Ne5+ Ke7 3. Nxd3 cxd3 4. Bxd3 Nxb4! knight sacrifice (4... Rf3? 5. Be4 Rg3+ 6. Kh4 Rxc3 7. Bxd5 +-) 5. cxb4 Rxb4 = 2... Rxg4+! rook sacrifice 3. Kxg4 Nf6+ 4. Kf4 Nxh7 4... Bxh7? 5. Ke5! Ng4+ 6. Kd4 +- 5. b5 Nf8! 6. Ke5 Ng6+ 7. Kf6 Kd6 8. Rc6+ Kd7 9. Rc5 Kd6 positional draw

Solution: 1. Bg8+ Kd6 2. Rc6+! rook sacrifice (2. Bxd5? Rf5+ 3. Kh4 Kxc7 =) 2... Kxc6 3. Bxd5+ Kd6! The black king triangulates! (3... Kxd5 4. Kxf4 black is in zugzwang Be2 (4... Ke6 5. Ne5 Be2 6. Ke4 +-) 5. Ne3+ Ke6 6. Ke4 +-) 4. Kxf4 Kxd5


1st cyclic zugzwang - WTM

In order to win, white must reach the same position but with black to move. The shortest manoeuvre to pass the move to black lasts 35 moves! All moves from the cycle are unique optimal moves. 5. Ne3+ (5. Nf2?! Be2 6. Kf5?! Bd3+ 7. Kf6? Bc2! 8. Ke7 Ba4 =) 5... Ke6 6. Nd1 Kd5 7. Nb2 White threatens to bring the knight to c5. 7... Bc2! 8. Kg5 Bd3 (8... Ke4 9. Kf6 Kd5 10. Ke7 Bf5 11. Kd8 +-) 9. Kf6 (9. Na4? Ke5 =) 9... Kd6 White should bring the knight to a5 before he continues the king manoeuvre. 10. Nd1! (The shortest path to a5 via a4-c5-b7 doesn't work: 10. Na4?! Be4 11. Nc5 Bc6!; If the king starts the manoeuvre too soon, its knight gets stuck on b2: 10. Kf7?! Bf1 11. Ke8 Be2 12. Kd8 Kc6! 13. Ke7 Kb5! Now, in order to win, white has to free its knight... 14. Ke6 Bg4+ 15. Ke5 Bf3 16. Kf4 Be2 17. Ke3 Bh5 18. Kd2 Bg6 19. Ke2! Quicker than the immediate 18.Nd1. It is better to lure the bishop to f5 first using a triangulation. 19... Bh5+ 20. Ke3 Bg4 21. Kd2 Bf5 22. Nd1 Now the knight is free but also the black king! 22... Kc6 23. Ke3 Kd5 24. Nb2 Bg6 25. Kf4 Bc2 and we have returned to a previous position from the main line) 10... Be4 11. Ne3 Bd3 12. Ng4 Be2 13. Ne5 Bd3 14. Nf7+ Kd5 This move blocks the a8-h1 diagonal allowing the knight to go to b7. (14... Kd7 15. Ke5 +-) 15. Nd8! Kd6 16. Nb7+ Kc7 17. Na5! (Moving immediately to c5 is wrong: 17. Nc5?! Kd6 and the white king cannot move to f5.) 17... Kd6 18. Kf7 Kd7 19. Nb7! Black is in zugzwang! 19... Be2 (The bishop cannot move to the big diagonal: 19... Be4 20. Nc5+ +-) 20. Kf6 Kc7 21. Nc5 Kd6 22. Kf5 The bishop was not on d3! 22... Kd5 23. Kf4 Bf1 This is a new cyclic zugzwang position! (23... Bd3 24. Nxd3 cxd3 25. Ke3 Kc4 26. Kd2 +-)


2nd cyclic zugzwang - WTM

White will lose a tempo by a square-shaped manoeuvre (Nc5-d7-f6-e4-c5) while the black king triangulates (Kd5-d6-e6-d5). 24. Nd7 (It is too early to bring the knight to a4: 24. Na4? Be2 25. Ke3 Bd3 White is in zugzwang! 26. Nb6+ Kc6 27. Nc8 Kc7 28. Ne7 Kd6 29. Ng8 Ke5) 24... Kd6 25. Nf6 Ke6 26. Ne4 Kd5 27. Nc5


2nd cyclic zugzwang - BTM

27... Be2 28. Na4! Bd3 29. Ke3 Black is in zugzwang! The bishop has to leave the good square from which it controls the b1-h7 diagonal. 29... Bf1 30. Nb6+ Ke5 (In the following variation we can see the drawback of leaving the b1-h7 diagonal: 30... Kc6 31. Nc8 Kc7 32. Ne7 Kd6 33. Ng6! Kd5 (33... Bd3 34. Nf4 +-) 34. Kf2 Bd3 35. Nf4+ Ke4 36. Nxd3 Kxd3 37. b5 +-) 31. Kf3! This is a waiting move to lure the bishop to d3! (The immediate Nd7 is refuted by Ke6. 31. Nd7+?! Ke6) 31... Bd3 32. Nd7+ Kd6 (Ke6 is not that strong anymore: 32... Ke6 33. Nc5+ Kd5 34. Nxd3 cxd3 35. Ke3 Kc4 36. Kd2 +-) 33. Nc5 By attacking the bishop, white wins a crucial tempo. The black king cannot go back to the fifth rank, so the bishop must control e4. That means it has to leave the d3-f1 diagonal. 33... Bf5 The bishop also takes under control the important d7 square. 34. Kf4! (34. Ke3?! would throw away all the progress we have done so far. Ke5 M111 35. Na4 Bd7 36. Nb2 Be6 37. Kd2 Bd5 38. Nd1 Be4 39. Ne3 Bd3 40. Ng4+ Kf4 41. Nf6 Bf5 42. Nd5+ Ke4 43. Ne3 Be6 44. Nc2 Bg4 45. Nd4 Ke5 46. Kc1 Kd6 47. Kc2 Bh5 48. Nf5+ Ke5 49. Ne3 Bf7 50. Kb2 Ke4 51. Nc2 Bh5 52. Nd4 Kd5 53. Ka3 Bd1 54. Nf5 Kc6 55. Ne3 Bb3 56. Kb2 Kc7 $1 57. Nf5 Ba4 58. Kc1 Kd7 59. Nh6 Kd6 60. Kd2 Ke5 61. Ke3 Bd1 62. Nf7+ Ke6 63. Ng5+ Ke5 64. Ne4 Bc2 65. Nd2 Bd3 66. Nf3+ Kd5 67. Nh2 Bc2 68. Kf4 Bb1 $1 69. Ng4 Bd3 and we have returned to the cyclic zugzwang position from the main line) 34... Bg6 35. Ke3 Kd5 (35... Ke5 36. Nd7+ now that the bishop has left f5 this move works Kd5 37. Nb6+ +-) 36. Nd7 The threat is Nb6+ 36... Bd3 37. Nf6+ Ke5 38. Ng4+ Kd5 39. Kf4 +-


1st cyclic zugzwang - BTM

Watch this study on a dynamic board! Click here!



This study is based on the following computer endgame which is the longest win for KNPPKBP:

M. Bourzutschky & Y. Konoval
EG#188
2012

"For the KNPPKBP endgame the longest win is 102 moves and there is only one record position." 1. Na3 Kg2 2. Nb5 c6 3. Nd4 c5 4. Nb5 Kg3 5. Nc7 Bc8 6. Na8 Ba6 7. Nb6 Kf4 8. Nd7 c4 9. b4 Bb5 10. Nc5 Ke5 11. Nb7 Bc6 12. Na5 Bb5 13. Kb2 Kd5 14. Nb7 Bc6 15. Nd8 Kd6 16. Nf7+ Ke6 17. Nh6 Ke5 18. Kc2 Bd5 19. Ng4+ Kf4 20. Nf2 Bf3 21. Kc1 Kf5 22. Kd2 Ke5 23. Ke3 Bg2 24. Nd1 Bh3 25. Kd2 Bf5 26. Ne3 Bd3 27. Ng4+ Kf4 28. Nf6 Bf5 29. Nd5+ Ke4 30. Ne3 Be6 31. Nc2 Bg4 32. Nd4 Ke5 33. Kc1 Kd6 34. Kc2 Bh5 35. Nf5+ Ke5 36. Ne3 Bf7 37. Kb2 Ke4 38. Nc2 Bh5 39. Nd4 Kd5 40. Ka3 Bd1 41. Nf5 Kc6 42. Ne3 Bb3 43. Kb2 Kc7 44. Nf5 Ba4 45. Kc1 Kd7 46. Nh6 Ke6 47. Kd2 Ke5 48. Ke3 Bd1 49. Nf7+ Ke6 50. Ng5+ Ke5 51. Ne4 Be2 52. Nd2 Bd3 53. Nf3+ Kd5 54. Nh2 Be4 55. Kf4 Bg6 56. Ng4 Bd3 57. Ne3+ Ke6 58. Nd1 Bc2 59. Nb2 Kd5 60. Kg5 Bd3 61. Kf6 Kd6 62. Nd1 Be4 63. Ne3 Bd3 64. Ng4 Be2 65. Ne5 Bd3 66. Nf7+ Kd5 67. Nd8 Kd6 68. Nb7+ Kc7 69. Na5 Kd6 70. Kf7 Kd7 71. Nb7 Be2 72. Kf6 Kc7 73. Nc5 Kd6 74. Kf5 Kd5 75. Kf4 Bf1 76. Nd7 Kd6 77. Nf6 Ke6 78. Ne4 Be2 79. Nc5+ Kd5 80. Na4 Bd3 81. Ke3 Bf1 82. Nb6+ Ke5 83. Kf3 Bd3 84. Nd7+ Kd6 85. Nc5 Bf5 86. Kf4 Bg6 87. Ke3 Kd5 88. Nd7 Bd3 89. Nf6+ Ke6 90. Ng4 Kd5 91. Kf4 Be2 92. Ne3+ Kc6 93. Kf5 Bd3+ 94. Ke5 Kb6 95. Nf5 Kb7 96. Nd4 Ka6 97. Ke6 Be4 98. Nf5 Bc6 99. Nd6 Ba4 100. Ke5 Bb3 101. Kd4 Kb6 102. Nxc4+ +- "Attention, please! After 9.b4!! White has to make 92 moves without moving a pawn and capturing. A surprising example of a 50 move rule exception!"

Study 141

Árpád Rusz
Krug-50 JT
2017
Commendation

White wins

1. Nc5 h2 2. Ne4 Kf4 2... h1=Q 3. Ng3+ +- 3. Nf2 Kf3 4. Nh1 Kg2 5. Ke3 Kxh1 6. Kf2 c5 7. d3 a4 8. Bb2

a. 8... c4 9. dxc4 9. d4? c3! 10. Bxc3 a3 11. Ba1 a2 12. d5 stalemate 9... a3 10. Ba1! echo 10. Bxa3? stalemate

10... a2 11. Kg3 Kg1 12. Bd4+ Kh1 13. Kh3! 13. c5 a1=Q 14. Bxa1 Kg1 15. Bd4+ Kh1! -+ 13... a1=Q 14. Bxa1 Kg1 15. Bd4+ Kh1 16. Be5 Kg1 17. Bxh2+ +-

b. 8... a3 9. Bxa3 c4 10. d4! 10. dxc4? stalemate 10... c3 11. Bc1! echo

11... c2 12. Kg3 Kg1 13. Be3+ Kh1 14. Kh3! c1=Q 15. Bxc1 Kg1 16. Be3+ Kh1 17. Bf4 Kg1 18. Bxh2+ +-

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Study 140

Árpád Rusz
Krug-50 JT
2017
Commendation

Draw

1. h7 Nf5! Black doesn't capture the c2 pawn anticipating a NN/P endgame with a harmful pawn! 1... Nxc2 2. h8=Q Bxd4+ 3. Qxd4 Nxd4 4. Nxb4! Nxb4 = 2. h8=Q Bxd4+ fork 3. Qxd4 Nxd4 4. Nxb4! 4. c4? bxc3 e.p. -+; 4. Kb7? Nc3! 5. Nxb4 Kxb4 -+ 4... Nxb4


refusal to fork

5. c4!! 5. c3? fork 5... Nbc6+! (5... Ndc6+? 6. Ka8! Nd3 7. c4 Nc5 stalemate) 6. Ka8!? (6. Kb7 Nd8+ 7. Kc7 N4c6! 8. c4 Ka6 9. c5 Ka7 -+ The white king cannot reach a8, the only safe corner if the pawn is blocked on c5.) 6... Ne6 7. c4 Ka6! Black doesn't block the pawn and lets it pass the Troitzky line! (7... Nc5? stalemate) 8. c5 Nc7# 5... Ne6 6. c5! Now it is too late to stop the pawn because it has passed the Troitzky line. 6... Nc6+ 7. Kb7 (or 7. Ka8 Kb5 8. Kb7 Ned8+ 9. Ka8) 7... Ned8+ 8. Ka8! White still has to be very careful! Even if the pawn has passed the Troizky line, a8 is the only safe corner. 8... Ne6 8... Kb5 stalemate 9. Kb7 Ned4 10. Ka8! positional draw - fortress 10. Kc7? Ka6 -+

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