How about:

W: Kh1, Pg2, Pg6, Ph7, Pb3, Pa4
B: Kh8, Pg7, Pg3, Ph2, Pb6, Pa5


(Bill Brock) wrote in message . com...
(Bill Brock) wrote in message . com...
"Bill Smythe" wrote in message ...
Here's a more genuine chess quiz question (sorry to put a wet blanket on
your attempts at humor, Sam):

Is there such a thing as a SYMMETRIC position in which, no matter whose move
it is, the player on the move loses, with best play by his opponent?

SYMMETRIC means that, for example, if white has a knight on e3, then black
has a knight on e6.

Bill Smythe

The first position that occured to me was...

whoever moves loses
White: Ke5, Pd4
Black: Kc4, Pd5

...but there's no axis of symmetry here (it would work on a 9 x 8 board!).

I bet there are quite a few such positions....

here are four (eight if you count queenside reflections, which I
wouldn't):

White to move, Black wins

1)
White: Kf3, Pf2, Ph6, Pf5
Black: Kf6, Pf7, Ph3, Pf4

2)
same as 1), shifted one file to the left
White: Ke3 etc

3)
White: Kh3, Ph2, Pf6, Ph5
Black: Kh6, Ph7, Pf3, Ph4

4)
same as 3), shifted one file to the left
White: Kg3 etc

Same trivial idea in all four: many other positions could obviously be
constructed using this one-move mutual zugzwang (by adding pawns &
tempo moves on queenside, e.g.)

A more interesting task: are there any such symmetrical zugzwang
positions in which the winning side (Black) crosses the barrier
between 4th & 5th ranks to win? In other words, the mutual zugzwang
is "full-court," not "half-court"?

"Bill Brock" wrote:
here are four ....

"Bruce Leverett" wrote:
W: Kh1, Pg2, Pg6, Ph7, Pb3, Pa4
B: Kh8, Pg7, Pg3, Ph2, Pb6, Pa5

Aw, phooey. You guys have made this too easy.

The position I had in mind (not entirely dissimilar to the above) was:

W: Ka3, Pa2, Pb2, Pb3, Pb4, Pd4, Pe2
B: Ka6, Pa7, Pb7, Pb6, Pb5, Pd5, Pe7

-- and the question then is, HOW does the second player win? (It's not
quite as easy as Bruce's.)

Bill Smythe

"Bill Smythe" wrote in message ...
"Bill Brock" wrote:
here are four ....

"Bruce Leverett" wrote:
W: Kh1, Pg2, Pg6, Ph7, Pb3, Pa4
B: Kh8, Pg7, Pg3, Ph2, Pb6, Pa5

Aw, phooey. You guys have made this too easy.

The position I had in mind (not entirely dissimilar to the above) was:

W: Ka3, Pa2, Pb2, Pb3, Pb4, Pd4, Pe2
B: Ka6, Pa7, Pb7, Pb6, Pb5, Pd5, Pe7

-- and the question then is, HOW does the second player win? (It's not
quite as easy as Bruce's.)

Bill Smythe

Underpromotion is a nice touch (you'd shown me this problem before,
but I'd forgetten).

New tasks:

Are there symmetrical mutual zugzwang positions in which the winning
King crosses the median (from 5th to 4th rank)? My guess is no....

How about Knight endings?

How about Rook endings?

"Bill Brock" wrote:
.... you'd shown me this problem before,
but I'd forgetten). ....

Yeh, I've probably inflicted this one on just about everybody I've met at
any club or tournament.

Even more often have I inflicted the following:

white: Kf2, Rb1, Rh7.
black: Ka8, Rg2.

How does white win?

Bill Smythe

"Bill Smythe" wrote in message ...
"Bill Brock" wrote:
.... you'd shown me this problem before,
but I'd forgetten). ....

Yeh, I've probably inflicted this one on just about everybody I've met at
any club or tournament.

Even more often have I inflicted the following:

white: Kf2, Rb1, Rh7.
black: Ka8, Rg2.

How does white win?

Bill Smythe



Something Smythetudinous:

Kasparian, 1937

White: Ke8, Pa2,b2,b4,b5
Black: Ka8, Pb7,h6

White to play and draw

The idea may be obvious, but the execution isn't....

"Bill Brock" wrote:
White: Ke8, Pa2,b2,b4,b5
Black: Ka8, Pb7,h6
White to play and draw

Well, I'll give up for the time being. Obviously, the idea is something
like getting the king to a5 surrounded by a bunch of white pawns, but the
obvious attempted solutions seem a move or two short (as usual in a good
problem).

I could mention that, obviously, 1.Kd7 (or 1.Ke7 or 1.Kf7) forces 1...h5 (if
black wants to avoid an immediate draw) lest white get inside "the square".
By similarly forcing an h-pawn push on every move, white can prevent, for a
while, ...b7-b6, which looks important. But that's as far as I have the
patience for right now.

Bill Smythe

"Bill Smythe" wrote in message ...
"Bill Brock" wrote:
White: Ke8, Pa2,b2,b4,b5
Black: Ka8, Pb7,h6
White to play and draw

Well, I'll give up for the time being. Obviously, the idea is something
like getting the king to a5 surrounded by a bunch of white pawns, but the
obvious attempted solutions seem a move or two short (as usual in a good
problem).

I could mention that, obviously, 1.Kd7 (or 1.Ke7 or 1.Kf7) forces 1...h5 (if
black wants to avoid an immediate draw) lest white get inside "the square".
By similarly forcing an h-pawn push on every move, white can prevent, for a
while, ...b7-b6, which looks important. But that's as far as I have the
patience for right now.

Bill Smythe

The first four moves go pretty much as you predict: 1.Kd7 h5 2.Kc7 h4
3.Kb6 h3 4.Ka5 h2 (not 4...b6?! 5.Ka4!). Then what?

On 4 Nov 2004 16:55:47 -0800, (Bill Brock)
wrote:

"Bill Smythe" wrote in message ...
"Bill Brock" wrote:
White: Ke8, Pa2,b2,b4,b5
Black: Ka8, Pb7,h6
White to play and draw

Well, I'll give up for the time being. Obviously, the idea is something
like getting the king to a5 surrounded by a bunch of white pawns, but the
obvious attempted solutions seem a move or two short (as usual in a good
problem).

I could mention that, obviously, 1.Kd7 (or 1.Ke7 or 1.Kf7) forces 1...h5 (if
black wants to avoid an immediate draw) lest white get inside "the square".
By similarly forcing an h-pawn push on every move, white can prevent, for a
while, ...b7-b6, which looks important. But that's as far as I have the
patience for right now.

Bill Smythe

The first four moves go pretty much as you predict: 1.Kd7 h5 2.Kc7 h4
3.Kb6 h3 4.Ka5 h2 (not 4...b6?! 5.Ka4!). Then what?

OK. Now 5. b6 h1=Q 6. b5 Qb1 7. a4 and I do not see how White can be
stopped from playing b4 and it is stalemate.

Sam Sloan

White: Ke8, Pa2,b2,b4,b5
Black: Ka8, Pb7,h6
White to play and draw

Bill Brock wrote:
The first four moves go pretty much as you predict: 1.Kd7 h5 2.Kc7 h4
3.Kb6 h3 4.Ka5 h2 (not 4...b6?! 5.Ka4!). Then what?

"Sam Sloan" wrote:
OK. Now 5. b6 h1=Q 6. b5 Qb1 7. a4 and I do not see how White can be
stopped from playing b4 and it is stalemate.

Ouch!! I got that far, but stupidly did not realize (egg on my face) that
after 7.a4 the b-pawn cannot be captured.

However, I have another concern. (Maybe I'll have more egg on my face after
somebody explains this one.) What if, instead of 2...h4, black plays
2...b6? The refutation suggested for the same idea at move 4 is not
available at move 2, and black still has plenty of time to queen the pawn.

Bill Smythe

White: Ke8, Pa2,b2,b4,b5
Black: Ka8, Pb7,h6
White to play and draw

1.Kd7 h5 2.Kc7 h4
3.Kb6 h3 4.Ka5 h2 (not 4...b6?! 5.Ka4!)
5. b6 h1=Q 6. b5 Qb1 7. a4 ....

I wrote:

However, I have another concern. (Maybe I'll have more egg on my face
after
somebody explains this one.) What if, instead of 2...h4, black plays
2...b6? The refutation suggested for the same idea at move 4 is not
available at move 2, and black still has plenty of time to queen the pawn.
.....

Ooh, I do indeed have egg on my face (but I am hereby wiping it off myself).
In this variation white draws as follows:

1.Kd7 h5 2.Kc7 b6 3.Kc6 h4 4.Kd5 h3 5.Kc4 h2 6.Kb3 h1=Q 7.Kh4 with
the same idea as in the main variation.

Of course, if at any time black moves his king instead of pushing the
h-pawn, white still plays the same moves.

Bill Smythe