## Sunday, January 04, 2009

### The twelve puzzles of Xmas

White to play and mate in:

(a) half a move
(b) a third of a move
(c) a fifth of a move

#### 7 comments:

an ordinary chessplayer said...

The only 1/2-move problem I have seen before involved removing the captured en-passant pawn. On those lines:
(a) 1. Qb7# - releasing the queen which was previously picked up.
(b) 1. Qd8# - replacing the pawn which advanced from d7.
(c) 1. Qd8# - replacing the pawn which captured from e7.

But I don't like my (b), as using the same mathematics as (a) and (c) gives a different result: Pick up the d7-pawn, release on d8, pick up the d8-pawn, finally releasing the new queen is 1/4 of a move and not 1/3.

Maybe someone else has a better answer?

Anonymous said...

Completely and utterly confused.

Adam B.

Neill Cooper said...

I think this one is a bit too under-speciifed for me to solve. The only half moves I know are Castles. I could say a) Qd8 (from f6); b) Qd8 (from g5) c) Qd8 (from d3).

Still, thanks for all the 12problems, which I have enjoyed

Anonymous said...

Absorbing puzzle series, EJH.

Like Neill I am flummoxed by this one. Can you tell us the answer?

Angus

ejh said...

Yes, sorry, I've been ill for a few days but I'll try and get my act together tomorrow and give the solution and sources.

(I should note that it's not a very serious solution.)

Anonymous said...

Well, I guess 2-piece puzzles are a little short on the ground...

Angus

ejh said...

Blimey, I forgot all about this!

Anyway, here's the late, late solution. The puzzle is from Chess, December 1973, Hugh Courtney's much-missed Christmas Quiz, though Mr Courtney ascribed it to Leonard Barden in the Guardian Chess Book. Courtney gives the hint

"think of the actual actions involved manually as you make a move"

and then gives the following solution which I give in the original descriptive:

(a) White puts his queen down on Q8 (giving mate): the first half of the move had been picking it up from Q1!

(b) The complete move here is QxR (Q8): White had already completed the first two parts of this move, i.e. he had picked up his queen, and he had picked up the black rook with his other hand, so that the one third of the move left to make was to put his queen down on Q8!

(c) A five-part single move is involved here, but I'm sure you've guessed!? P(K7)xR(Q8)=Q. Do I hear any groans?