[Retros] Win by capturing opponent's king

[Andrew Buchanan]

If the game is won by capturing the opponent's king, then really the check
rule must go too. Because otherwise someone who is about to have their king
taken has no legal final move.

Because of this, we can construct positions where it is *faster* to force
capture of the king than to mate:

http://www.janko.at/Retros/d.php?ff=7k/5P2/8/5K2/8/8/8/8
(a) Mate in 3.
(b) [Capture the king] Win in 2.

Cheers,
Andrew.

-----Original Message-----
From: retros-bounces at janko.at [mailto:retros-bounces at janko.at] On Behalf Of
Francois Labelle
Sent: 21 December 2012 00:35
To: The Retrograde Analysis Mailing List
Subject: Re: [Retros] Solidarity chess (=SC)

Thanks. I managed to screw up my example (the WK should be put elsewhere to
prevent 1.Rxh1 gxh1=Q+), but you get the idea: a mate in n can become a draw
(just remove the WR from my diagram), or it can become a win in > 
n+1 if we feel like composing a bit.

     Francois

On 12/20/2012 01:33 AM, Eric Angelini wrote:

>> The position below

> ... is just beautiful -- bravo François!

> (I have to admit that things are more subtle than I thought -- even in 

> orthodox chess...) Best, É.

>

> -----Message d'origine-----

> De : retros-bounces at janko.at [mailto:retros-bounces at janko.at] De la 

> part de Francois Labelle Envoyé : jeudi 20 décembre 2012 9:51 À : The 

> Retrograde Analysis Mailing List Objet : Re: [Retros] Solidarity chess 

> (=SC)

>

> On 12/19/2012 05:40 PM, Noam Elkies wrote:

>> Eric Angelini <Eric.Angelini at kntv.be> writes:

>>

>>> I know that I am not allowed to put delibarately my King in check -- 

>>> but how does this affect the chess game where the only rule is: - 

>>> you win the game by capturing the opponent's King, period?

>> No real difference as long as you're concerned only with orthodox 

>> play (wins stay wins, "mate in n" becomes "win in n+1", etc.).

> I don't think so! The position below is a "mate in 1" which becomes a 

> "win in 3" if we need to capture the opponent's King:

>

> http://www.janko.at/Retros/d.php?ff=K6R/8/8/2N5/8/8/1pppppp1/brrqkrrb

>

>       Francois