[Retros] Retro_snippets_001 - Schnoebelen Promotion / the Pawn case

[raosorio at fibertel.com.ar]

Dear friends,
Here follows an antecedent of Pawn Schnoebelen,

Roberto Osorio - RML february 16th 2006
rnb2bnk/pppp1p2/1q1p4/8/7p/2N5/PQP1P1PP/R1B1KBNR
PG in 22 single moves Singular on GOS>>
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Solution,
a) Stipulation: single box type II
b)sequence:
1.- d4,h5 2.- d5,h4 3.- d6,exd6 4.- f4,Qf6 5.- f5,Qxb2 6.- f6,Qb6
7.- f6xg7,ke7 8.- g7xh8,Kf6(h8 can't be bishop or queen)
9.- Qd4+,Kg6(h8 can't be a knight) 10.- Qb2,Kh7(h8 can't be a rook)
11.- Nc8,Kxh8 (Schoenebelen pawn).

Singular PG on GOS is not an stipulation but a master characteristic. Solution is 
unique not only in a given stipulation but in an extended space of many stipualtions.
(the concept is explained in my february 2006 mails to the RML).

the main idea is that the solver has to find not only the sequence but first of all the chess
stipualtion (within a set of Geometrically Orthodox Stipulations, GOS). The above PG could be
presented directly as "single box type II" and it would be correct,  but this presentation is
much weaker since the sequence is unique not only in the "single box type II" space but in
an extended space of many stipùlations (which clear up the potential of "single box type II"
to allow a Pawn Schnoebelen.)

best,
Roberto