#### Posers and Puzzles

Mislav
Posers and Puzzles 07 Sep '05 19:02
1. 07 Sep '05 19:02

After reading "Chess mysteries of Sherlock Holmes" by Raymond Smullyan I got inspired and created my first retrograde problem, I hope everything is correct. 🙂

(1) In this game, no piece or pawn has moved from a white square to a black one, and vice versa.

(2) Prove that white can't castle.
2. BigDoggProblem
Court Jester
07 Sep '05 20:001 edit
Originally posted by Mislav
[fen]r1b1k3/1p1p1p2/8/8/8/8/8/R3K2R w KQkq - 0 1[/fen]

After reading "Chess mysteries of Sherlock Holmes" by Raymond Smullyan I got inspired and created my first retrograde problem, I hope everything is correct. 🙂

(1) In this game, no piece or pawn has moved from a white square to a black one, and vice versa.

(2) Prove that white can't castle.
The problem is unsound. One possible gamescore is:

1.g4 h5 2.d4 hxg4 3.f4 gxf3 4.Bh6 fxe2 5.Bxg7 exd1=B 6.Bxf8 Bxc2 7.Bxe7 Bxb1 8.Bd6 Qg5 9.Bxc7 Qxg1 10.Bxb8 Qxh2 11.Bxa7 Qxb2 12.Bd3 Qxd4 13.Bh7 Qb2 14.Bd4 Bxa2 15.Bxh8 Qxh8 16.Bxg8 Bb1 17.Bh7 Qb2 18.Bxb1 Qa3 19.Rxa3 Ra4 20.Bd3 Ra8 21.Ba6 Rxa6 22.Ra1 Ra8

and now...

23.O-O!
3. 07 Sep '05 20:211 edit
Originally posted by BigDoggProblem
The problem is unsound. One possible gamescore is:

1.g4 h5 2.d4 hxg4 3.f4 gxf3 4.Bh6 fxe2 5.Bxg7 exd1=B 6.Bxf8 Bxc2 7.Bxe7 Bxb1 8.Bd6 Qg5 9.Bxc7 Qxg1 10.Bxb8 Qxh2 11.Bxa7 Qxb2 12.Bd3 Qxd4 13.Bh7 Qb2 14.Bd4 Bxa2 15.Bxh8 Qxh8 16.Bxg8 Bb1 17.Bh7 Qb2 18.Bxb1 Qa3 19.Rxa3 Ra4 20.Bd3 Ra8 21.Ba6 Rxa6 22.Ra1 Ra8

and now...

[b]23.O-O!
[/b]
Seems like you are right. 🙁
Sorry for posting incorrect problem.
Could this be an improvement? I think without possibility of en passant for black problem should be correct. But maybe you will refute me again. 😀
4. BigDoggProblem
Court Jester
08 Sep '05 00:56
Originally posted by Mislav
Seems like you are right. 🙁
Sorry for posting incorrect problem.
Could this be an improvement? I think without possibility of en passant for black problem should be correct. But maybe you will refute me again. 😀
[fen]r1b1k3/1p1p1p2/8/8/8/8/5P2/R3K2R w KQkq - 0 1[/fen]
So the reasoning goes:

- The Knights did not move at all.
- Who captured Nb1? Ra8 can never reach b1, so only Ph7 is left.
- Ph7 needs to capture at least 4 times to promote.
- White did not promote on light squares (too few captures available).
- White sacrificed 2P (e- and -g or g- and h-) and Q and B to bPh7.
- bRa8 made Black's last light-squared capture.
- After Ph7 promoted and captured Nb1, it was not captured by wQ or wB (already gone) or wP (would need to capture twice - once to kill the promoted piece, and again to be killed by bRa8). Therefore, wRh1 made the capture and returned.
- wK or wRa1 made the last capture on dark squares, then returned. This is an easy one, because black has nothing left on light squares, and even en passant will not help white save his castling rights, because the pawn must immediately retract to its starting square, and thus it can never capture.
5. BigDoggProblem
Court Jester
08 Sep '05 05:35
Here is great problem using a similar condition.

Monochrome Chess
Where were all the Rooks captured? Who captured them?

In Monochrome Chess a piece may not move to squares of different color than the square it occupies. This is a bit different than a game 'where no piece has changed square color' - it is perfectly legal for the Kings to stand adjacent in Monochrome Chess.
6. 08 Sep '05 09:40
Apart from the obvious White castling kingside and the knight at d1 being promoted (maybe via capturing the h1 rook?!), this problem requires some effort... I'll give it some thought.