Benko-Kortschnoi: Riddle solved

Riddle solved: Benko missed a hidden win

The duel "bishop against knight" is tricky and often leads to long manoeuvring. At the Candidates Tournament 1962 in Curacao Pal Benko had such an endgame against Viktor Kortschnoi.

Karsten Müller asked the readers to help analysing this endgame.

Pal Benko

In fact, Benko missed a deep and hidden win.

Usually, the bishop strives for dynamic play while the knight prefers more static positions. In this case, after 46...h3, Benko's knight has everything under control and all the time in the world. However, it still takes some time before it is apparent how White can win.

Kevin Cotreau and Scorpion29 found correct solutions.

Zoran Petronijevic once again sent in the best solution.

Conclusions:

1. The starting position is a draw.
2. 46...h3? is a grave error after which Black is lost.
3. Benko missed a hidden win, and after his move 57.Nh7? Black could have defended.
4. Benko and Timman think that 62.Kg3 is a mistake but the position is already a draw and the move is not a mistake. Benko and Timman propose 62.Ke2 but this, too, is not enough for a win.
5. Benko and Timman also think that 64...Kc4 is an error. But even after this move the position is still a draw.
6. The decisive mistake is 66...Kd3?. After this move Black is lost.

Solution:

Magical Chess Endgames

In over 4 hours in front of the camera, Karsten Müller presents to you sensations from the world of endgames - partly reaching far beyond standard techniques and rules of thumb - and rounds off with some cases of with own examples.

Our reader Ted Jewell wanted to know more about Zoran Petronijevic, who again and again provided the best solutions to Karsten Müller's Endgame Riddles, and he invited Zoran to an interview to gain insights into his analytical methods:

Are you a strong player? Do you have a FIDE-rating or a title?

I am an International Master with a current rating of 2405. However, in 2003 I have stopped to play over-the-board chess. By profession I am a teacher for philosophy and logic, but currently I am unemployed.

Since 2003 I have worked as a chess coach online and that makes me happy. Occasionally, I play some blitz chess on sites such as playchess.com, ICC, chess.com, lichess.... My handle is "zoranp".

In chess I try to find the truth, or at least, to come closer to it. I regularly analyse games for the Chess Informant where I have a small column about endgame errors. A long time ago, I also made a CD for ChessBase about Caro-Kann. Moreover, I edited and revised two parts (pawn endings and rook endings) of the Encyclopedia of Chess Endings which is  published by Chess Informant.

Which engines do you use? How long do you let the computer run on a particular line? How deeply do you go into a line before ending the search and moving to another variation?

I use Stockfish 11 – usually the latest version. Before I let an engine analyse a game, I analyse myself on the board to try to find the most important ideas. How deep we should analyse with an engine depends on the complexity of the position. We should know in which positions the engine can help us, and in which positions it is helpless (or almost helpless). In sum: if we want to find the best moves, we need to have an understanding of chess.

Do you do much of the analysis yourself? Or do you let the computer analyze various branches and then assemble the results?

I always analyze on the board first, and only afterwards with an engine. I steer the engine through the variations – not the other way round – particularly in positions, in which the engines are not that strong. In positions, in which there is no clear plan (or in which there is a deep, hidden plan) the engines are not particularly useful. In fact, analysing on the board without the help of engines is one of my passions.

Do you research all published analysis of the game, which you want to analyse, first? Do you do anything in particular before using an engine?

If the game is well-known, yes. One should know where previous analysts stopped. Of course, you should check their analyses before you go deeper into the position. E.g., the last riddle that was published on the ChessBase website (Schlechter-Lasker) has been heavily analysed and there were a lot of important analyses one should simply know and check. I therefore own a decent number of chess books (about 2,000).

Tu sum it up again: to analyse well, you have to know something about chess. Engines do not understand some typical positions, some well-known endgame ideas, fortresses, etc... But you should know this. Because I no longer play tournament chess, I hardly ever analyse openings. I mainly analyse middlegames and endgames.

Thank you for your time and insights!

Links

• Historical riddle: Schlechter vs Lasker 1910
• Riddle solved: Lasker was winning
• Historical riddle: Petrosian vs Tal, Curacao 1962
• Riddle solved: Tal could have drawn!
• The historical puzzle: Botvinnik vs Bronstein 1951    
• Solution to the historical riddle Botvinnik vs Bronstein 1951: Bronstein could have drawn
• How sound was the endgame Spielmann-Rubinstein?
• Riddle solved: Spielmann could have drawn!
• Could Petrosian have held against Fischer?
• Petrosian could have held!
• The old riddle of Fischer vs Taimanov
• Riddle solved: Fischer was winning
• The old riddle of Botvinnik vs Fischer
• Riddle solved: Fischer could have won
• Historical riddle: could Kramnik have defeated the computer?
• Kramnik could have defeated Fritz