# An original retro problem

• 3 years ago · Quote · #1

Hey guys, I composed the following puzzle.

Take a look at this position, and try to answer these two questions:

1) If it is white to move, can he possibly castle?

2) If it is black to move, can he possibly castle?

• 3 years ago · Quote · #2

Well, here goes. White's a pawn evidently promoted to a dark square bishop, so it's not as simple as "promoted on a8 so black can't castle."

But black can't castle, since his king must have moved to allow the rook in.

As for white - I'm stuck.

• 3 years ago · Quote · #3

How did the bishop get to a3 without a dark-squared pawn moving?

• 3 years ago · Quote · #4

I agree, the a3 bishop must have been a promotion.

But the g7 Rook cant get there without the white king moving, so white cant castle either

• 3 years ago · Quote · #5
rooperi wrote:

I agree, the a3 bishop must have been a promotion.

But the g7 Rook cant get there without the white king moving, so white cant castle either

Sounds right to me. I thought "the rook came out, so white can't castle - wait, no, Black's knight could have taken the rook." But, of course, it was still on the board!

• 3 years ago · Quote · #6

Yeah both kings had to move. Unless white's bishop is actually a grasshopper.

• 3 years ago · Quote · #7

There is one "trick" that you guys are not considering. There is another way to get a rook out of this particular pawn chain, it a rather common maneuver in these sort of problems, which is good to know. It goes like this:

• 3 years ago · Quote · #8

lol. I knew I should stay out of this. I'll get my coat....

• 3 years ago · Quote · #9

That doesn't help black any. However, it looks like work needs to be done for white again.

• 3 years ago · Quote · #10

Anyway, if it's white to move, why bother? He can win either rook he chooses with his hanging rook :)

(Just kidding, I know it's a puzzle).

• 3 years ago · Quote · #11

I don't have time right now to look at this more deeply, but on second glance, black's king need not necessarily have moved for the white rook to get to g7.  A similar analysis also implies that the white king might not have had to move.

The pawns on g6 and h6 don't have to have simply moved forward.  They could have cross-captured.  The sequence of moves would be like this:

White places a piece on h6

Black captured gxh6

White moves his rook to g8

Black moves his bishop to g7

White places a piece on g6

Black captures via hxg6

Black moves his rook to h7 and then his bishop to h8

White moves his rook to g7.

Of course, for this to work, black has to move his king in order to not get checked by the rook on g8.  So, I guess that means that, even in this case, black's king had to move.

A similar maneuver could have occurred to let the white rook out of h1 without making the white king move.

• 3 years ago · Quote · #12

There is a very good reason why I hate chess puzzles. I should have just quietly walked on by...If I leave now I can catch rooperi.

• 3 years ago · Quote · #13

White obviously cannot castle. He captured the bishop on c8 and his a-pawn made 3 captures (to promote to a dark-square bishop), leaving none for the g and h-pawns to change files. That leaves no path to g7 for the kingside rook... unless of course the White king has moved ;)

Black can castle, however, if the game went something like this:

• 3 years ago · Quote · #14
cobra91 wrote:

White obviously cannot castle. He captured the bishop on c8 and his a-pawn made 3 captures (to promote to a dark-square bishop), leaving none for the g and h-pawns to change files. That leaves no path to g7 for the kingside rook... unless of course the White king has moved ;)

Black can castle, however, if the game went something like this:

Look who's back.

If I knew I'd have the honor of you solving my puzzle, I'd at least try to make it more challenging

• 3 years ago · Quote · #15

@cobra: see post 7. I don't think you've proved that kingside rook can't get to g7 without the white king moving...

• 3 years ago · Quote · #16

@Timothy: He proved.

White could (actually he has) capture 3 times with pawns. The 2 black knights and the queen.
He required 3 captures to promote a-pawn on b8 or d8.
No captures left for gxh3 and hxg3.

=> Rg7 had to pass e1 to get to either a1 or g7
=> King moved/castled
=> No more castling