Last Move?

BigDogg

Secret RHP coder

Posers and Puzzles

03 Sep 05 20:24

ilywrin

Joined: 30 Oct 04
Moves: 7813

07 Sep 05 10:29

Originally posted by BigDoggProblem
Can you prove it?

Well, how else could the Black bishop have gotten to a1?

BigDogg

Secret RHP coder

on the payroll

Joined: 26 Nov 04
Moves: 155080

07 Sep 05 14:14

Originally posted by ilywrin
Well, how else could the Black bishop have gotten to a1?

Another piece could have captured on b2 (no reason it has to be a Bishop), or White could simply move the b-pawn. It could then be taken later by any black piece, or sacrificed on c4 instead of the a-pawn.

crazyblue

Joined: 29 Apr 05
Moves: 827

07 Sep 05 17:26

But then there wouldn't be enough pieces for the black g-pawn to get to b2 (and from there promote to a1 to a bishop), wasnt it that?

BigDogg

Secret RHP coder

on the payroll

Joined: 26 Nov 04
Moves: 155080

07 Sep 05 19:33

Originally posted by crazyblue
But then there wouldn't be enough pieces for the black g-pawn to get to b2 (and from there promote to a1 to a bishop), wasnt it that?

Ba1 isn't a promoted Bishop. The last move was ...b1Q#.

Coconut

Earth Prime

Joined: 16 Mar 05
Moves: 35265

07 Sep 05 19:52

Originally posted by BigDoggProblem
Ba1 isn't a promoted Bishop. The last move was ...b1Q#.

OMFG!11!!!!

I pmed that to you. So what if I had no proof?

BigDogg

Secret RHP coder

on the payroll

Joined: 26 Nov 04
Moves: 155080

07 Sep 05 20:05

Originally posted by Coconut
OMFG!11!!!!

I pmed that to you. So what if I had no proof?

lol, then I'd have to credit several people who got the right last move with wrong or incomplete reasoning. Unfortunately, the problem is a bit weak in forcing the solver to 'prove it'.

SicilianNajdorf

London

Joined: 30 Aug 05
Moves: 1250

08 Sep 05 16:08

Since the White king is in check , Black's move was probably taking on g3 so it must be fxg3+ or hxg3+ , g3 is not possible becuase the pawn would occupy the king's square.

SicilianNajdorf

London

Joined: 30 Aug 05
Moves: 1250

08 Sep 05 16:08

Since the White king is in check , Black's move was probably taking on g3 so it must be fxg3+ or hxg3+ , g3 is not possible becuase the pawn would occupy the king's square.

BigDogg

Secret RHP coder

on the payroll

Joined: 26 Nov 04
Moves: 155080

08 Sep 05 16:21

Originally posted by SicilianNajdorf
Since the White king is in check , Black's move was probably taking on g3 so it must be fxg3+ or hxg3+ , g3 is not possible becuase the pawn would occupy the king's square.

It is possible to prove where the black pawn came from and what type of piece it captured.