Endgame riddle solved: 50 moves are just enough

by Karsten Müller
4/25/2021 – In the endgame riddle from 15 April ChessBase readers were invited to analyse an interesting and complicated endgame knight vs bishop. In the game E. Torre vs O. Jakobsen, Amsterdam 1973, from which the riddle was taken, the knight defeated the bishop, but Karsten Müller wanted to know whether the knight would also have won against best defense. Now, he has the answer.

Chess Endgames 14 - The golden guidelines of endgame play Chess Endgames 14 - The golden guidelines of endgame play

Rules of thumb are the key to everything when you are having to set the correct course in a complex endgame. In this final DVD of his series on the endgame, our endgame specialist introduces you to the most important of these rules of thumb.


Riddle solved: Torre's 66th move was a mistake

This riddle was complicated and in some lines Black wins just before the 50-move rule would have led to a draw. It is amazing to see what the knight must do to outfox the bishop.

It was Charles Sullivan (USA) who proposed to have a closer look at this riddle, and as usual Zoran Petronijevic suggested a lot of lines and also formulated the conclusions, which Charles Sullivan then edited slightly:

The endgame in E. Torre-O. Jakobsen, 1973: Conclusions

1. The initial position after Black's 65th move should lead to a draw with best play from both sides though Black has more space for maneuvering.

2. White's 66th move is a premature attempt to trade pieces which could have led to a losing position.

3. ChessBase reader "malfa" suggested 67...c5 as a possible win for Black, and he is right!

4. After 74.Bf1? White is lost. Better was 74.Be2 which saves a draw. Of course, in a practical game it isn’t possible to find the difference between these two moves. Even in analysis it is hard to see a difference.  

5. After 78…Kxc5 Black has a won position but a huge problem: the 50-moves rule. If Black does not move a pawn or capture a piece in the next 50 moves, the game will be declared drawn.

6. 80…Ka5 is a mistake which allows White to make a draw due to 50-moves rule. After 80…Kc6, however, Black is winning in time.

7. The game move 82.Kd2 holds the draw and 82.Kc4 also leads to a draw.

8. 83.Be2 is the *decisive* mistake which loses. After 83.Kd3! White can draw due to the 50-moves rule!  It is interesting that Timman  mentions 83.Kd3 loses (in: Jan Timman, Power Chess With Pieces, New In Chess 2004.

9. 84.Bd1 is imprecise because it makes Black's task easier. After the better 84.Kd3 Black must play precisely to avoid a draw because of the 50-moves rule.

10. 88…Kd3 is imprecise. Better is 88…Kc4.

11. 90….Kd2 is not the best. Better is 90…Nb5.

12. 93…Nb1 is not the best. Better is 93…Kc2.

13. 103.Bb5 helps Black. After 103.Bc4 Black would need to play flawlessly to win within 50 moves.

In his book Power Chess With Pieces, mentioned above, Jan Timman told the following anecdote: "The impossibly tall Danish master was so proud of his endgame technique that he showed the final stages of the game to Spassky, who was playing in the Main Group and happened to be talking to me at the time. I remember that Spassky was hardly impressed. 'These manoeuvres are characteristic for this type of endgame,' he said matter-of-factly, leaving a rather disconcerted Jakobsen, who had spent countless hours analysing this endgame, in his wake." (p. 92).

It would be interesting to know Spassky’s opinion of this modern computer-assisted analysis, in which Black sometimes requires a really crazy knight maneuver to win and to avoid the 50-moves rule.



Karsten Müller, born 1970, has a world-wide reputation as one of the greatest endgame experts. He has, together with Frank Lamprecht, written a book on the subject: “Fundamental Chess Endgames” in addition to other contributions such as his column on the website ChessCafe as well as in ChessBase Magazine. Müller's ChessBase-DVDs about endgames in Fritztrainer-Format are bestsellers. The PhD in mathematics lives in Hamburg, where he has also been hunting down points for the HSK in the Bundesliga for many years.
Discussion and Feedback Join the public discussion or submit your feedback to the editors


Rules for reader comments


Not registered yet? Register

Karsten Müller Karsten Müller 4/27/2021 12:26
With additional h-pawns Dvoretzki has looked at this endgame deeply:
"Lieber Herr Dr. Müller,

vielleicht wäre es mit Blick auf die Lösung des Schachrätsels (E. Torre
- O. Jacobsen) hilfreich, die Leser auf die Analyse Dvoretzkis in seinem Buch "Geheimnisse gezielten Schachtrainings" - dort S. 100 ff. - hinzuweisen, die sich bei vertauschten Farben ebenfalls mit der behandelten Endspielstruktur befasst. In seiner mehrseitigen Untersuchung behandelt Dvoretzki eingehend auch das Thema "Schlüsselfelder", das in der Lösung des aktuellen Endspielrätsels nicht erwähnt wird, dort womöglich aber gleichermaßen von Bedeutung sein könnte.

Sollte Spassky die Analyse Dvoretzkis (einer Partie aus dem Jahre 1966) beim IBM-Turnier 1973 bereits bekannt gewesen sein, kann seine von Timman wiedergegebene Aussage zu diesem Endspieltypus kaum mehr verwundern.

Mit freundlichen Grüßen

Horst Rauer

Mitglied der Schachabteilung des SV Werder Bremen"
Karsten Müller Karsten Müller 4/25/2021 02:54
malfa: Yes 66.Bc4!? is probably the best practical choice.
malfa malfa 4/25/2021 02:48
Thanks for quoting my contribution.
I should add that some days after the end of the original discussion it occurred to me that, whereas 66.Kd3 could still offer Black some practical chances, 66.Bc4! should be a really shellproof defence, further dominating the Nc7 and offering the right piece to the exchange. In this case Black doesn't even manage to plant a knight on d4, whereas White will calmly strengthen his position by means of Kd3-c3 in order to eventually improve his knight. Of course any exchange of a knight for the bishop, either via the immediate 66...Nxc4 Nxc4, or via 66...Nb5 67.Bxb5 cxb5 would then produce an easily drawn knight endgame. What do you think?