Weird Position Challenge

Originally posted by geepamoogle
(Just as a matter of record, double check is only possible by means of discovery where the piece moving out of the way also threatens to take the king.)

This statement is false!

Originally posted by artplayer
Actually I think this position is possible: the last move played was c5xd5+.

If white just captured en passant, then black's last move had to be d7-d5, blocking the check from the wB on h1. I do not see any legal way white could have delivered that check.

Originally posted by artplayer
Actually I think this position is possible: the last move played was c5xd5+.

White is in check from two places...I don't think it is legal in this setup.

right. A slightly care-free answer on my part. Still looking for a solution-

Originally posted by SwissGambit
[fen]8/8/2kP4/5r1b/8/6Kp/7P/2R2bBB b - - 0 1[/fen]
Is the position legal?
a) diagram
b) wQh1 instead of wB

Edit: Prove your answer.

Alright. I think I've got the solution. All or nothing, here's my final answer. I'm positive the position with the f1 B is illegal. As far as I can tell the only way that the bishop could have administered the check is by the king moving out of the way. The king could have been on f3, with the previous position (diagram)



black just played Bh5+... with the continuation of 1. g4 f4xg4+ en passant 2. kxg3+ d5 2. c5xd5+ en passant. The only issue is that the B could never have made it to h1 without the g2 pawn moving, thus making the f4xg4 en passant and black's double check and the position illegal.

The only issue is that the B could never have made it to h1 without the g2 pawn moving, thus making the f4xg4 en passant and black's double check and the position illegal.

That's why putting a queen there instead makes the position legal.

Originally posted by Jirakon
The only issue is that the B could never have made it to h1 without the g2 pawn moving, thus making the f4xg4 en passant and black's double check and the position illegal.

That's why putting a queen there instead makes the position legal.

Correct. The answer for a) is "no" and b) is "yes".

cool. That was a fun one SwissGambit kept me thinking about it almost all day.

J.Lois, 1981

Add a White piece and 2 bP for an Illegal Cluster
Five solutions

Illegal Cluster: An Illegal position that becomes legal if any unit (besides a King) is removed.

I call it the high class swindler!

Originally posted by artplayer
I call it the high class swindler!

[fen]6bk/6Pp/3p3K/2p2qnP/1p6/8/7r/8 b KQkq - 0 1[/fen]

That's the kind of swindle that can only be pulled off with whiskey.

The thing I love about this position is that White has a 466 to 3 material advantage over Black, yet Black can mate in one and White can't.

Originally posted by SwissGambit
That's the kind of swindle that can only be pulled off with whiskey.

lol

Originally posted by Jirakon
[fen]QQQQQQQQ/QQQQ1QQQ/QQRBRKQQ/QQBQBQQQ/QQRNRQQQ/NQnQQQQQ/1RQQQQQQ/k1NQQQQQ[/fen]

The thing I love about this position is that White has a 466 to 3 material advantage over Black, yet Black can mate in one and White can't.

nice one 🙂

Thank you.