[Retros] Haaner Chess

[Bernd Schwarzkopf]

Am 22.08.2018 11:44, schrieb Otto Janko:
> Dear Retro Community,
>
> Fairy chess rules are often poorly documented. My current questions are
> related to "Haaner Chess", see problem P0007610 in the PDB.
>
> The stipulation reads "What was the position 65 single moves ago? (Haaner
> Chess)"
>    
The stipulation is
"Wie war die Stellung vor 62 Einzelzügen?" (not 65)
("What was the position 62 single moves ago?")
The condition is wrong. It should be: "Haaner Partieschach".

The problem was one of 12 diagramms in an article in which I introduced the new condition "Haaner Partieschach" (Haaner Chess beginning with the first move of a prove game [Partieanfangsstellung]). My idea of the condition was to have a Haaner-condition which has the possibility to construct retro problems. (In "Haaner Schach" the rule [normally] begins with diagram position.)

So in (C) feenschach 47, VII-IX 1979, page 156 the stipulation is the same as
"shortest prove game in 62 single moves (this game is not unique), Haaner Chach from the beginning".
The idea of C was to construct a very long prove game (as long as possible), further more with the kings in the region of the other side. The solotion was published in the same issue on pagr 155 (diagram3 and text).

> The interesting wording is "from the diagram position" ("ab der
> Diagrammstellung"). This refers clearly only to forward play. But what about
> backward play? Is P0007610 already full of holes?
Yes. It ist the end of an game - with the condition "Haaner Schach" from 
the beginning.
> Can a knight jump over a hole?
>    

Yes, a knight can jump, but not a Queen, Rook, Bishop (or white 0-0-0 
with a hole b1).
> What about capturing promotions? Does the promotee stand on hole after a
> capture? Or are capturing promotions illegal?
>    
wPb7, bSc8
1.b7xc8=Q (hole on b7, no more holes)
The capturing promotion is is possible. It is one move; after the normal 
move the square (which became empty) becomes a hole.

wPb5, bPc7
1.c7-c5 (hole on c7) b5xc6 ep (holes on b5 and c5)

wKe1, wRa1
1.0-0-0 (holes on e1 and a1)

ep-capture and casteling are the only moves in which two holes are 
created (with orthodox men and rules).

Best regards
Bernd