[Retros] Task - double check mate

[Allan Bell]

----- Original Message ----- 
From: "Noam Elkies" <elkies at math.harvard.edu>
To: <Nicolas.Dupont at math.univ-lille1.fr>; <retros at janko.at>
Sent: Sunday, September 24, 2006 2:49 AM
Subject: Re: [Retros] Task



> > In the web-site "France-Echecs", I proposed the following problem :

> > Construct the shortest possible exact proof game ending by a check-mate

> > given by a piece returning at home.

>

> What's the link?

>

> > Here are our records, the 2 sections depending on whether or not

> > some piece is captured during the game  :

>

> There could also be separate sections for discovered, direct

> and double check (though of course not all pieces can do

> all of them).


As suggested by Noam, here is a double check-mate (with captures) given by
a piece returning to its home square.  Both checks are required.

1.Pa2-a4   Pe7-e5   2.Ra1-a3   Ke8-e7   3.Ra3-e3   Ke7-d6
4.Sb1-c3   Kd6-c5   5.Pb2-b4   Kc5xb4   6.Bc1-a3   Kb4xa3
7.Qd1-b1   Pb7-b5   8.Qb1xb5   Bf8-b4   9.Ke1-d1   Pd7-d6
10.Kd1-c1   Bc8-f5   11.Kc1-b1   Bf5xc2   12.Kb1-a1   Pf7-f5
13.Sc3-b1

C+ Natch

But there must be a shorter setting.

Allan Bell


>

> > Knight with capture : not least [...]

>

> What does "not least" mean?

>

> > Rook without capture : 9 moves (Itamar Faybish)

>

> This at least is not optimal:

>

> 1 f3 h5 2 Kf2 h4 3 Qe1 h3 4 Kg3 Nf6 5 Qf2 Rg8 6 Kh4 Se4 7 g3 f5 8 Qg2 Rh8#

>

> (C+ Popeye very quickly), and one can probably go below 8.0

> with some more effort.

>

> --Noam D. Elkies

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