We found a cook in the printed version (Black could prepare a forward defense). A correction (wRc2) was published in the solutions section.
Basisplan: -1.Qb5-b2? (Probespiel) threatens -2.Qa6-b5 and 1.Rxb6#
if
-1…Sb4/b8-c6, then -2.Sc6-a5 and 1.R(x)b8#
if
-1…R~-d8, then -2.Qd3-b5 and 1.Qxd7#
duals after some Black retractions that do not parry the threat need not
be mentioned.
but
-1…O-O-O! unique refutation! (Hindernis)
-2.O-O
and 1.Rh8#? (thematic mate by
White) is illegal because both uncastlings are
mutually exclusive: If
the black dark-squared bishop was promoted on c1 (bPbxc>c1=B), the wPd had
to promote on f8, capturing dxexPf>f8=R (dxcxb>b8=R? – bPf is unaccounted
for); both balances are closed (counting bPhxwBg, wPh2>h8=R, wPb2>b8=R) and
Black cannot uncastle until unpromotion on f8. If the bishop was promoted on e1,
then wPdxc, wPcxb>b8=R, b2>b8=R, wPh2>h8=R), both balances are closed
again and this time White cannot uncastle before unpromotion on e1.
Sicherungsplan: -1.O-O? (Probespiel) with
the purpose of illegalizing Black’s refutation and threatening to execute the Basisplan.
-1…R~-d8 -2.Qb5-b2 Kd8-c8
-3.Qd3-b5 and 1.Qxd7#
but -1…Rh8-d8 and 1…Rxh1#! (forward
defense) (Sekundärhindernis). Notice that
this is a unique refutation that has to be played immediately. Notice also that
the Sekundärhindernis was not set in the diagram position, but is a
consequence of the Sicherungsplan.
Zweckökonomie: after the
maneuver (-1.O-O any) White has gained nothing for the Basisplan but the
elimination of the Hindernis.
Lösungsablauf
Sicherungsplan: -1.Rf3-c3 with the purpose of
neutralizing the Sekundärhindernis and threatening with the immediate
execution of the Basisplan due to the opening of the a1-h8 diagonal:
-2.Qb5-b2 O-O-O -3.Qb2-b5 (switchback) and 1.Qh8#. Obviously, the key also
provides for an immediate uncastling by Black. Black has to defend with -1…Qa1-b1. Notice that the first Sicherungsplan
is still needed: -2.Qb5-b2? O-O-O! -3.Qb2-b5? threatening with -4.Qg7-b2 and
1.Qg8# but -3…Sd4(e5)-c6! -1…g7-g5? (closing of the a1-h8 diagonal) is
illegal! -1…Sc3-a4? (closing of the a1-h8 diagonal) but -2.c4-c5!
Sd4-c6+ -3.Sc6-a5 and 1.Rb8#.
Zweckökonomie: after the
maneuver (-1.Rf3-c3 Qa1-b1) White has gained nothing for the Basisplan or for the first Sicherungsplan but the
elimination of the Sekundärhindernis.
Sicherungsplan: -2.O-O any (no forward defense)
Basisplan: -3.Qb5-b2! threatens -4.Qa6-b5 and 1.Rxb6#;
if
-3…Sb4/b8-c6, then -4.Sc6-a5 and 1.R(x)b8#
if
-3…R~-d8, then -4.Qd3-b5 and 1.Qxd7#
-3…O-O-O is illegal.
