Guidance for solvers

• Introduction

  The Postal round has always been accompanied by guidance for solvers about what constitutes a full solution to the different types of problem set. Nevertheless, this year (2002-2003) there has been some confusion about what is expected of solvers and so I have prepared this separate page of guidance.

  I shall be adding some flesh to these bare bones (including examples) in the next day or two.

  The Final of the BCSC has always been inspired by the World Chess Solving Championship (WCSC). The types of problems set, the time limits used and the solving rules have always been based on those used by the WCSC. The solving rules for the Postal Round, apart form two small differences, are the same as for the final.

  Here is what the WCSC rules say about what solvers have to give in their solutions:

  • “8. The solutions are to be written in the following way:
    • a) in direct mate problems: all moves in all variations of full length including the threat if it is of full length too except the last move of Black and the mating move, i.e. in twomovers only the key; in threemovers all three move variations, including the threat, up to the second white move, etc.
    • b) in helpmate problems: all moves;
    • c) in selfmate problems: all moves except the mating move in all variations of full length, including the threat if it is of full length too,
    • d) in endgames: all moves up to an obvious win or draw.

    If a threat is not written all required variations (according to a,c,d) are to be given.

  • 9.1. In problems for which more than one solution is indicated the solver has to give the requested solutions. In all other problems and endgames only one solution is to be given.

  • 9.2. If a solver believes he has found a cook, he may give it instead of the solution. In this case, he has to give the complete moves of the cook according to point 8. The correct and complete solution or cook of a problem scores 5 points.

  • 9.3. The complete solution may consist of several single solutions.

  • 9.4. An incomplete solution scores fewer points. Incorrect or incomplete variations - when more than one solution is especially indicated, incorrect or incomplete single solutions - score 0 points.

  • 9.5 The Director must determine the distribution of points for a solution (i.e. for different variations, moves or single solutions) before the tournament starts.

  • 9.6. If a problem has no solution, 0 points are awarded for this problem and all solvers get the full time score in this round.

  • 9.7. Retro problems and problems with fairy conditions (see 6.3.) are treated like problems with no solution. A problem with an illegal position is treated like one with a legal position.

  • 10. If a move is written incorrectly, unclearly or ambiguously, this variation or single solution is regarded as incorrect. If, however, the Director (or the jury, pt 13.5) is absolutely sure that the correct move was intended, this variation or single solution must be regarded as correct”.

• Directmates

  The WCSC rules say this about the solutions required for directmates:

  “... in direct mate problems: all moves in all variations of full length including the threat if it is of full length too except the last move of Black and the mating move, i.e. in twomovers only the key; in threemovers all three move variations, including the threat, up to the second white move, etc. ... If a threat is not written all required variations ... are to be given.”

• Selfmates

  The WCSC rules say this about the solutions required for selfmates:

  “... in selfmate problems: all moves except the mating move in all variations of full length, including the threat if it is of full length too, ... If a threat is not written all required variations ... are to be given.”

• Helpmates

  The WCSC rules say this about the solutions required for helpmates:

  “... in helpmate problems: all moves ...”

• Endgame studies

  The WCSC rules say this about the solutions required for endgames studies:

  “... in endgames: all moves up to an obvious win or draw ... If a threat is not written all required variations ... are to be given.”

• Further reading

  Anybody interested should go and have a look at the full rules of the World Chess Solving Championship, though they won't find anything else about what's required from solvers.

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