Legal position?

Originally posted by heinzkat
Yes... therefore the previous moves cannot have been d4-d5+, e7-e5, d5xe6 e.p.+, since White cannot have played d4-d5 while his own King was in check. Therefore, the first position is illegal.

With the wK->d7 the previous moves can/must have been (in order to reach the position) d4-d5+, e7-e5. d4xe6 e.p.+.

I welcome better thought out explanations.

(on a sidenote, 'can have been', is there a better construction to say this?)

I would just say that in b), the last moves had to be -1.dxe6 ep e7-e5 -2.d4-d5+, and in a), -1...e7-e5 is illegal check to wK. The minus sign in front of the move number denotes retraction.

Now, two challenges:

Construct a legal position in which it is possible to prove that there were TWO e. p. captures.

Do the same for THREE e. p. captures.

Originally posted by David113
Now, two challenges:

Construct a legal position in which it is possible to prove that there were TWO e. p. captures.

Do the same for THREE e. p. captures.

How many halfmoves would you have to 'get' for the two e.p. captures? And for three? I suppose MORE THAN six [edit two seconds later; oh probably six halfmoves is just enough]. Seems a tough exercise?

I think the edit to the above message is not correct - anyway I think I have found the first task... (although it might be cooked, up to you to point out where)

Originally posted by heinzkat
I think the edit to the above message is not correct - anyway I think I have found the first task... (although it might be cooked, up to you to point out where)

[fen]5Q1R/8/4PPk1/8/6K1/8/P7/BB5R[/fen]

Looks cooked. -1.e5xf6ep f7-f5 -2.e4-e5 Kf6xNg6 -3.Ne5-g6+.

Originally posted by SwissGambit
Looks cooked. -1.e5xf6ep f7-f5 -2.e4-e5 Kf6xNg6 -3.Ne5-g6+.

Thanks for the flaw finding - I had thought of pieces that 'added' (were captured by Black), but could not find this one. Now what can be done to uncook it? Probably this whole set-up doesn't work?

Here is my highly sophisticated, elegant, second try:

Unless I'm a total dolt, that looks like an en passent for mate... very purdy!

Originally posted by Gastel
en passent

It is a reaction to David's problem.

As the philosopher Freud once said,"Chess is more confusing than the man that mixes whiskey with vodka". Therefore, I conclude that this chessboard is actually a mirror image of the original. For reference, read the book Pawn and Beer by the renowned Dr. M. Msimang.

Originally posted by heinzkat
Here is my highly sophisticated, elegant, second try:

[fen]N4Q1R/N7/1PP1PPk1/8/6K1/6P1/P4PP1/BB5R[/fen]

Looks sound to me.

Well now the task of three en passants... any set-up ideas, anyone?

Originally posted by heinzkat
Well now the task of three en passants... any set-up ideas, anyone?

Using Smullyan double-checks, we can get two ep without using all 16 white units:



But I'm not sure where a 3rd ep would fit in this scheme.

swissgambit... you and your smullyan double checks... *ruffles hair*

Originally posted by SwissGambit
N. Høeg
FIDE Album 1914-44
[fen]bN6/pPkR3p/PpPpPP2/8/2KP4/B6B/1q1P2PQ/br1R2Nr[/fen]
What were the last 13 single moves played?

Originally posted by SwissGambit
This was the task David113 asked for a while back - 3 en passant captures in a retro.

I guess we can call this SOLV'D, David?