[Retros] How many times could a Diagram be repeated during aproofgame?

Rol, Guus G.A.Rol at umcutrecht.nl
Mon Jun 4 12:38:27 EDT 2007

Hi Roberto,

Considering that:

(a) only one of the two e.p. rights can be active in a proof game
(b) repeating a diagram with the same player on move requires 2 moves
(c) a move change in an identical diagram requires 3 moves
(d) the drawn position can still be part of the proof game
(e) the number of retractions is one less than the number of positions
(f) the number of diagram repetitions is one less than the number of
diagram occurrences,

I think the minimum number of single retraction moves for the maximum of
21 diagram repetitions is 46 (=5x9+1).

Cheers, Guus Rol.

> -----Oorspronkelijk bericht-----

> Van: retros-bounces at janko.at [mailto:retros-bounces at janko.at]

> Namens raosorio at fibertel.com.ar

> Verzonden: maandag 4 juni 2007 0:53

> Aan: retros at janko.at

> Onderwerp: [Retros] How many times could a Diagram be

> repeated during aproofgame?



> Hi,


> Thanks to Alexander and Tom for their comments.

> They are wright having in mind I made a not proper

> presentation. Sorry, I assumed that being this a retro forum

> it would be understood by default that I was referring "under

> retro conventions" but it was a mistake to state "legal"

> game. This suggests "real game", where the draw rules have to

> be claimed.


> Let's start again and present the issue as a retro problem.

> There are many examples of retros (in the FIDE albums for

> instance) showing that we agree on the automatic aplication

> of the draw rules in this type of problems.



> Let's define "Diagram" just as a board showing pieces on it,

> i.e., no matter at all anything regarding the right's status,

> not even who's to move. I present the following Diagram,


> r3k2r/8/2b5/Pp6/5BpP/8/8/R3K2R (just an example with the

> mimimal material)


> Questions:


> a) How many times could the Diagram have been repeated during

> the proofgame?


> b) How many retractions are needed to show these repetitions?


> (all the above following the retro conventions)


> I will post my own answers in few days but it would be

> interesting to have further interaction first (of course I

> could still be missing something).


> Best,

> Roberto Osorio


> --------------------------------------------------------------

> --------------------------------------------------------------

> -----------------

> If "legal" means _legal under FIDE tournament rules_, then I

> believe the answer to your first question, (a), is

> "Infinitely many times"; that is, there is no upper bound to

> the number of times a position may be repeated. I posted my

> reasons on ChessProblem.net a while back, and you can find

> them here: <http://chessproblem.net/viewtopic.php?t=127>.


> Regards,


> Alexander George


> --------------------------------------------------------------

> --------------------------------------------------------------

> ------------

> I agree completely with Alexander. As some relatively recent

> correspondence

> discussed, neither the repeated-position draw nor the

> 50-moves-without-pawn-move-or-capture draw are automatic (see

> FIDE Rules of Chess 9.2 and 9.3).


> Tom Volet



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