Spightonians/ Discussion

Sub-page of Spightonians

Should the term include captures?

Tom:I like the name!

I was going to suggest that the five-position situation should be considered both before and after the move. However, on reflection, it is very often the case that the fact of a capture is much more important than whether an empty triangle is made at the same time. So I suggest that it should be assumed that no capture is made for a Spightonian. This is pretty much what you have done, except that it would eliminate the final Spightonian, leaving 20.

(Sebastian:) You are right that when captures come into play, the distinction about what was there before becomes a bit moot. We could write this in the introducting paragraph. However, I would rather keep the name "Spightonian" for all 21 geometrically possible patterns - just as the periodic table ends with elements that hardly ever are realized.

New Spightonians?

Tom: Is there a reason that you haven't included the 'throw in'?

(Sebastian:) "throw in" seems to refer more to a tactical purpose of a move rather than a specific move shape itself. Could you draw the Spightonian for what you have in mind?

Borders

(Sebastian:) How do we include moves at the edge of the board in this list?

Close to the border
mirrored

Can we replace the border with mirrored points like this?

Missing Spightonians?

I (Malcolm) only counted 20 diagrams. Also, I didn't see the following diagrams :

Ripped keima plus one stone

Maybe I'm missing something.

(Sebastian:) The _ripped keima_ is a subclass of the tap (touching 1 enemy and 1 friend). But the _ripped keima plus one stone_ belongs to a class which I did indeed not list: touching 1 enemy and 2 friends. There are 6 such classes; I only listed classes that either already have names, or that contain important subclasses. There are more diagrams than listed classes, because some of them illustrate subclasses.

I see how it is confusing that I didn't mention that the page doesn't list all classes, so let's prepare a table. There are 15 different multisets with cardinality 4 of , and empty spaces. 6 of these (such as the tap and the thrust) have 2 different possible arrangements for the same number of stones. (These are the ones in which at least one element - either , , or empty space - has exactly 2 memberships.) I will call the two related arrangements "ortho-" and "para-", in analogy to the nomenclature for arene substitution patterns. In ortho-patterns, the dual-members occupy orthogonally adjacent places; in para-patterns, they occupy opposite places.

This gives us the following table of all possible classes. I indicated the unnamed patterns with systematic names in parentheses. If there is only one name in a cell, then there is no distinction between ortho- and para- patterns.

``` (arrangement) \  |       0       |       1       |       2       |       3       |       4      |
----------------------+---------------+---------------+---------------+---------------+--------------+
0 (ortho-)            | untouched     | touch         | carve         | (3e0f)        | gouge        |
0 (para-)             |               |               | general wedge |               |              |
----------------------+---------------+---------------+---------------+---------------+--------------+
1 (ortho-)            | narabi        | tap           | chop          | sashikomi     |
1 (para-)             |               | thrust        | impinge       |               |
----------------------+---------------+---------------+---------------+---------------+
2 (ortho-)            | straddle      | (1e2f.o)      | (2e2f.o)      |
2 (para-)             | botsugi       | (1e2f.p)      | division      |
----------------------+---------------+---------------+---------------+
3                     | (0e3f)        | (1e3f)        |
----------------------+---------------+---------------+
4                     | fill          |
----------------------+---------------+
```

Spightonians/ Discussion last edited by PJTraill on March 8, 2018 - 12:45
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