None attacked to All attacked

What is this site coming to when a guy can't even keep control of a hijacked thread. 😞

Anyway, this was buried in a thread about engine users.

Challenge: construct a legal position where A)White is attacking NONE of black's 16 pieces; but after he moves, he is B) attacking ALL of Black's 16 pieces.

"Attack" means "threaten to legally capture".

Good luck!

Originally posted by BigDoggProblem
What is this site coming to when a guy can't even keep control of a hijacked thread. 😞

Anyway, this was buried in a thread about engine users.

Challenge: construct a legal position where [b]A)White is attacking NONE of black's 16 pieces; but after he moves, he is B) attacking ALL of Black's 16 pieces.

"Attack" means "threaten to legally capture".

Good luck![/b]

Originally posted by DeepThought
[fen]3bQ3/4pppp/p1n2k1B/1p1r2N1/PNppP1n1/1PPq3b/r3BKPP/R2Q1R2 w KQkq - 0 1[/fen]
After Kg1 or Ke1 every black piece is threatened. The position is legal if implausible.

I can get as high as ten attack Black pieces after White's move. I'll be surprised if this can be improved upon.

Originally posted by BigDoggProblem
Ahh yes, I did leave this possibility open.

So I must add [b]C) white is not in check.[/b]

Unfortunately this doesn't quite comply with part A - "White is attacking NONE of black's 16 pieces". In fact 15 of Black's 16 pieces are under attack in the initial position!

I thought of another solution over lunch.

If White is one of four people playing that well known chess variant, 3d exchange chess (aka 3d bughouse), with the agreed rule that pieces can be put on with check, then in the following position:

Top board:


Middle board:


Bottom board:


He can play his queen to e4 in the middle board, simultaneously attacking all 16 of Black's pieces.

Last attempt. None of Black's pieces at start, all of them attacked after White's second move.

It can be done in orthodox chess in a single move.

Hint: Reveal Hidden Content

Thanks for the hint. I'm not happy with the white pawn on f6, but I can't get rid of it (stops white rook attacking f4):

Originally posted by Data Fly
Thanks for the hint. I'm not happy with the white pawn on f6, but I can't get rid of it (stops white rook attacking f4):
[pgn][/pgn]

Let's go for Nd5 instead then.

Originally posted by Data Fly
Unfortunately this doesn't quite comply with part A - "White is attacking NONE of black's 16 pieces". In fact 15 of Black's 16 pieces are under attack in the initial position!

Originally posted by Data Fly
Let's go for Nd5 instead then.
[pgn]
[FEN "5B2/1b2N1R1/1r1p1qP1/4p1p1/1r1p1p1p/2n1kN2/3p3p/4n1bK w - - 0 1"]
[SetUp "1"]
{
--------------
. k . q . B . .
r b . . N R . .
. . . p . P . .
n . . . p . p .
. r . p . p . p
. . . . . N . .
. . . p . . . p
. . . . n . b K
white to play
--------------
}
1. Nd5+
[/pgn]

Originally posted by BigDoggProblem
[b]Very good. That matrix is so good that I can get rid of two white units.