Go back
An easier

An easier "invalid move" problem

Only Chess

Vote Up
Vote Down

Black to move

It's a mystery position. One of the following moves is not possible - which one?

Bh1, g1=Q, Rhc1, Ng1

Vote Up
Vote Down

@bigdogg said
Black to move

It's a mystery position. One of the following moves is not possible - which one?

Bh1, g1=Q, Rhc1, Ng1
Here's my guess.

Bh1 and g1=Q are mutually exclusive because before either move, the g-pawn would have been at g2 and the bishop would have been on the h1/a8 diagonal. But the pawn would block the bishop from reaching h1.

Bh1 and Rhc1 are mutually exclusive because before either move, the rook would have been at h1, thereby preventing the bishop from moving there.

To resolve both of these conflicts by eliminating only one move, Bh1 must be eliminated.

Therefore, of the four moves given, Bh1 is the one that is not possible.

Vote Up
Vote Down

@fmdavidhlevin said
Here's my guess.

Hidden content removed
Correct.

Vote Up
Vote Down

Here's another one.

Find the invalid move in:
Nb1+, Bc1+, Qd1+, Ke1+, Bf1+, Ng1+

Vote Up
Vote Down

@bigdogg said
Here's another one.

Find the invalid move in:
Nb1+, Bc1+, Qd1+, Ke1+, Bf1+, Ng1+
Here's my guess.

Ng1+ is the invalid move, one construction being (in Forsyth notation)
8/8/8/8/R1Bk1B1R/2N5/5K2/B5Q1.

Vote Up
Vote Down

@fmdavidhlevin said
Here's my guess.

Hidden content removed
Correct!

You should try the one in Thread 199131. That one is the toughest of them all. No one has gotten it yet.

Vote Up
Vote Down

@bigdogg said
Correct!

You should try the one in Thread 199131. That one is the toughest of them all. No one has gotten it yet.
I've been avoiding it. 🙂 But maybe I'll tackle it.

Cookies help us deliver our Services. By using our Services or clicking I agree, you agree to our use of cookies. Learn More.