Joined: 05 Nov 2005
|Posted: Fri Oct 03, 2014 8:31 am Post subject: Block problems
|As you may have observed, I have set a few tutorial puzzles as an introduction to the art of chess compositions.
Usually these comprise of two puzzles: one very simple to show the theme and one more famous application of the theme.
But I feel that some subjects may need a bit more verbal introduction than practical within the puzzles themselves.
My next puzzles are "Block problems"- the topic of this post.
Direct mate problems are roughly divided in two main categories: (1) Threat problems and (2) Waiting problems based on the nature of the Key move (First move). The block problems belong generally to the second group. This means that their first move does not carry any direct mating threat, but simply waits for black to commit an unavoidable error.
* A "Complete Block" is a position, where for any black move there is a corresponding white mating move. (For a direct mate problem to have a solution black must be in complete block before black's last move).
*In an "Incomplete Block" there are some black moves without readily available mates. These must then be provided by previous white move. White's task is to complete the block. I have named this theme simply "Incomplete Block".
Let's consider a direct two move mate problem, where black stands in a complete block already in initial position. White's task then is to find a waiting move that preserves the mates inherent in the position. This is not always so easy. I have named this theme "Complete Block - preserve".
Sometimes it is not possible to preserve the mates existing in the initial position.[ By the way, these mates are called "Set mates" and the play (I.e. White 'passes' for his first move, black moves, white mates) is called "Set play".] In that case white has to find a waiting key move that do not preserve (all) the set mates, but instead provides alternative mates. These new mates are called "changed mates" or "mutates". I have named this theme "Complete Block - mutate".
I hope the above gives enough information about these themes. Remember (always) to check the set play. Incidentally it is one of the most powerful tools in solving a problem.
These tutorial puzzles are found as # 1546 - # 1551
There are only three kinds of chessplayers - those who can count and those who cannot....