[Retros] fractional moves: to be or not to be (Geurt Gijssen's answer)

raosorio at fibertel.com.ar raosorio at fibertel.com.ar
Tue Apr 22 16:17:49 EDT 2008


I reproduce here the Geurt Gijssen's answer (in his section "Arbiter's notebook", chesscafe)
to the question I made in february.

Your question is very interesting. Article 4.6 relates that a piece released on a square, provided the move is legal, cannot be replaced by another move. It also states that there are three types of moves that consist of two parts: capturing a piece, castling and promotion of a pawn. If the first part of a move is legal, then the player is forced to play the second part of the move as well. In case of Ke1-g1 nothing else can be played except the rook from h1 to f1. Therefore, I am inclined to consider Ke1-g1 as the first half of a legal move, not as an illegal move. Nevertheless, I shall discuss this case in Dresden during the meeting of the Rules and Tournament Regulations Committee in November 2008.

Hi retrofriends and Geurt,

I'm sending this with copy to the Retro mailing List and to the chess caffe.

On january 30th I made the following question,

"If the wK is standing on e1 and a wR on h1, castling is legal and posible but the player conducing the white side moves the King to g1 and that's it, he stops there. This move is illegal, but it's also a half legal move. Is white forced to move the king freely or he's forced to castle? "

Then I found article 4.6,

"4.6 When, as a legal move or part of a legal move, a piece has been released on a square, it cannot then be moved to another square.
b. in the case of castling, .... When the player has released the king from his hand, the move is not yet made, but the player no longer has the right to make any move other than castling on that side, if this is legal; "

I concluded that time that this answered all the questions, forcing in any case to castle. But I got another surprisse in my project related to ilegal situations. Art. 4.6 applies in the half move situation (the player has not pressed the clock) but in the case the player pressed the clock, then he made an ilegal move and the situation is governed by the article 7.4.a.,

"7.4.a. If during a game it is found that an illegal move.... has been completed, the position immediately before the irregularity shall be reinstated. .... Article 4.3 applies to the move replacing the illegal move. "

Then, in this case the move after the illegality is restricted by 4.3 instead by 4.6?! The 4.3 is the
"touched piece" article so the player is just forced to move the king freely, not to make castling.

Let's imagine the following situation,

I'm in the turn to move and I have doubts: is it better to play O-O or Kd1? Then, being an expert on the
fine details of the Laws, I move Ke1-g1 to have a look of this alternative a half move forward. My
opponent claims and the arbiter comes and, before he asked me to complete the castling, I press the
clock (I found that Kd1 was better). Consequences? A couple of minutes. Piece of cake!

Am I missing something here?

Roberto Osorio

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