[Retros] On the Jumanji convention

[Rol, Guus]

The new article 16 in the Codex - section (3) of which I baptized tongue
in cheek as "the Jumanji convention" - offers loads of material for
discussion. Werner Keym's clarification in the Retro Corner provides the
necessary background for its correct application. Careful reading
reveals that it provides not just one but two new meta-rules
(meta-conventions if you like), a fancy term for describing "rules about
rules". The first one says that "depending on rights analysis one must
apply either the RS or the PRA approach to solving the problem", the
second one that "in some of these cases the choice for RS or PRA further
depends on which one provides the most technically correct and content
rich solution to the problem". For the sake of simplicity one wonders
why not just one these meta-rules would suffice to achieve the objective
of article 16 section (3). The author explains that choosing between the
RS and PRA approach in mutually exclusive castling situations has proven
to be self-evident, but he omits claiming why this is not true for the
other right combinations. Actually, I am pretty sure the choice is just
as easy there and there is always the escape route in the RS/PRA
addition to the stipulation. Example IV (Ceriani) shows "2 mutually
exclusive castlings (black and white) and one e.p". Is this so different
from showing "1 white castling mutually exlusive with either of the
black castlings" or "2 mutually exclusive white castlings and an e.p.
move" that it warrants treatment by a different meta-rule? No, it is
not, and anyone new to this field would immediately agree to that. Which
points us to the political source of the distinction. In retro chess
history "mutually exclusive castling", like Excalibur after many
battles, has become the pre-eminent mythical retro-object, apparently
deserving of a deus ex machina convention all of its own. This is even
stranger when you consider that article 16, section (1) just by itself
generates the mutually exclusive castling phenomenon without the
slightest need to ever identify such a relationship. The new article 16,
with its historical ballast, will only contaminate the logical character
of the retro-space by inserting an arbitrary distinction and this may
deter potential participants in composing and solving retro-problems.

Article 16, section (3) has been named "the PRA convention", probably
since it reintroduced the obsoleted PRA term. I will not discuss the
rationale behind the renovated terminolgy at this point, but it should
be noted that section (3) is mainly dedicated to "the separation of RS
and PRA logics". The pendulum has swung from the mundane mind (the what
you can get away with RS-logic) to the scientific mind (the conditional
truth PRA/RV-logic). In doing so, once again the opportunity has been
missed for a principle based generic approach to the logics. PRA has
been specifically restricted to handle the castling and e.p. cases only,
ignoring the potential of repetition and 50M rules/conventions. More
importanly, it does not consider the scalability of retro-logics into
fairy-areas. Look e.g. at the implications of evaluating  "castling
rights" in Circe in conjunction with the resurrection of rooks! Not
mentioning "variable pieces" or "fuddled men" etc which will totally
take your head off. Isn't it funny that most of the chess rules are
comfortably replicated across the fairy-domain, but when it comes to
transforming the retro-logics, the required toolkit seems to be
completely missing?


Guus Rol.

 


-----Oorspronkelijk bericht-----
Van: retros-bounces at janko.at [mailto:retros-bounces at janko.at] Namens
Otto Janko
Verzonden: vrijdag 26 december 2008 18:00
Aan: Retros
Onderwerp: [Retros] Update if the Retro Corner

Dear Retro Friend,

The Retro Corner has been updated today:

. Stuttgarter Zeitung, Christmas Contest, 2008 

. "Partial Retrograde Analysis" and "Retro Strategy" in the modified
Codex (by Werner Keym, Meisenheim) 

More updates will follow in the next few days.

Best Regards,

- Otto Janko [mailto:otto at janko.at] [http://www.janko.at]
-- Those who desire to give up freedom in order to gain security,
- will not have, nor do they deserve, either one. [Benjamin Franklin]

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