On Sat, 20 Mar 2004 11:43:53 +0000 (UTC), Willem
wrote:

Mike wrote:
) Me: Black king in a corner
) You: White bishop right next to it, attacking it
) Me: White queen at the side of the black king

That's an illegal position, and it can never be made legal.

I agree. If you can create impossible positions like that, then you
can just stick the black king in a corner and surround him with a
layer of checking rooks, queens, bishops or whatever, then add a
couple knights to the mix on top of that!
--

On 20 Mar 2004 05:41:54 -0800, (Larry Tapper)
wrote:


Now there's no mate threat because of Rxa7.

This sequence also makes me wonder about the definition of "illegal
position". If a legal position is one that can only be reached by some
sequence of legal moves, then in a game starting with the first 3
moves above, White has not only failed to mate Black, he has shot
himself in the foot and will be unable to set up a checkmate for the
remainder of the game.


It looks like there's a rule floating here that we have to decide
whether or not to accept.

Here's the rule:
"There has to be a possible non-checking position that could have come
right before this checkmate."

In other words, the rule would say you don't have to worry about
having two bishops on white squares, etc., but there has to at least
be a previous possible position.


IF you follow that rule, THEN player #2 can always win.

And I'm willing to bet...
IF you don't follow that rule, THEN player #1 can always win (just by
dogpiling all over a king, checking him with two knights, a rook, a
queen, etc.

--

Dgates wrote in message . ..
On 20 Mar 2004 05:41:54 -0800, (Larry Tapper)
wrote:


Now there's no mate threat because of Rxa7.

This sequence also makes me wonder about the definition of "illegal
position". If a legal position is one that can only be reached by some
sequence of legal moves, then in a game starting with the first 3
moves above, White has not only failed to mate Black, he has shot
himself in the foot and will be unable to set up a checkmate for the
remainder of the game.


It looks like there's a rule floating here that we have to decide
whether or not to accept.

Here's the rule:
"There has to be a possible non-checking position that could have come
right before this checkmate."

In other words, the rule would say you don't have to worry about
having two bishops on white squares, etc., but there has to at least
be a previous possible position.


IF you follow that rule, THEN player #2 can always win.


And I'm willing to bet...
IF you don't follow that rule, THEN player #1 can always win (just by
dogpiling all over a king, checking him with two knights, a rook, a
queen, etc.

Yes I agree on both counts.

In the latter case, where multiple checks are allowed, here's a simple
winning strategy for Player #1:

1. Put the black king in the center.
2. Check with a white knight.
3. Check with the other white knight.
4. Fill up all the black king's remaining escape squares with random
pieces.

Then it's "mate", because both knights can't be captured at once.

Player #2 can't prevent any of this.

Larry

Larry Tapper wrote:

Dgates wrote in message . ..

On 20 Mar 2004 05:41:54 -0800, (Larry Tapper)
wrote:



Now there's no mate threat because of Rxa7.

This sequence also makes me wonder about the definition of "illegal
position". If a legal position is one that can only be reached by some
sequence of legal moves, then in a game starting with the first 3
moves above, White has not only failed to mate Black, he has shot
himself in the foot and will be unable to set up a checkmate for the
remainder of the game.


It looks like there's a rule floating here that we have to decide
whether or not to accept.

Here's the rule:
"There has to be a possible non-checking position that could have come
right before this checkmate."

In other words, the rule would say you don't have to worry about
having two bishops on white squares, etc., but there has to at least
be a previous possible position.


IF you follow that rule, THEN player #2 can always win.




And I'm willing to bet...
IF you don't follow that rule, THEN player #1 can always win (just by
dogpiling all over a king, checking him with two knights, a rook, a
queen, etc.


Yes I agree on both counts.

In the latter case, where multiple checks are allowed, here's a simple
winning strategy for Player #1:

1. Put the black king in the center.
2. Check with a white knight.
3. Check with the other white knight.
4. Fill up all the black king's remaining escape squares with random
pieces.

Then it's "mate", because both knights can't be captured at once.

Player #2 can't prevent any of this.

Larry

If I knew that was your strategy, I could easily prevent it. On
my first turn I'd put one white knight in a corner. That leaves
you only one of the white knights you need. (Not that I'm
disagreeing with the conclusion, only with the proposed method of
ensuring it.)

--
Mark Thornquist

Mark Thornquist wrote in message ...
Larry Tapper wrote:

Dgates wrote in message . ..
.... It looks like there's a rule floating here that we have to decide
whether or not to accept.

Here's the rule:
"There has to be a possible non-checking position that could have come
right before this checkmate."

In other words, the rule would say you don't have to worry about
having two bishops on white squares, etc., but there has to at least
be a previous possible position.


IF you follow that rule, THEN player #2 can always win.




And I'm willing to bet...
IF you don't follow that rule, THEN player #1 can always win (just by
dogpiling all over a king, checking him with two knights, a rook, a
queen, etc.


Yes I agree on both counts.

In the latter case, where multiple checks are allowed, here's a simple
winning strategy for Player #1:

1. Put the black king in the center.
2. Check with a white knight.
3. Check with the other white knight.
4. Fill up all the black king's remaining escape squares with random
pieces.

Then it's "mate", because both knights can't be captured at once.

Player #2 can't prevent any of this.

Larry

If I knew that was your strategy, I could easily prevent it. On
my first turn I'd put one white knight in a corner. That leaves
you only one of the white knights you need. (Not that I'm
disagreeing with the conclusion, only with the proposed method of
ensuring it.)

You're right, sorry. A sample winning sequence for Player #1 is:

Black king - d4, White knight - a8
White knight - b3, any
White rook - e4 or d5 "mate".

Clearly Dgates' "dogpile" strategy wins easily.

LT

On 23 Mar 2004 05:59:55 -0800, (Larry Tapper)
wrote:

Mark Thornquist wrote in message ...
Larry Tapper wrote:

Dgates wrote in message . ..
... It looks like there's a rule floating here that we have to decide
whether or not to accept.

Here's the rule:
"There has to be a possible non-checking position that could have come
right before this checkmate."

In other words, the rule would say you don't have to worry about
having two bishops on white squares, etc., but there has to at least
be a previous possible position.


IF you follow that rule, THEN player #2 can always win.




And I'm willing to bet...
IF you don't follow that rule, THEN player #1 can always win (just by
dogpiling all over a king, checking him with two knights, a rook, a
queen, etc.


Yes I agree on both counts.

In the latter case, where multiple checks are allowed, here's a simple
winning strategy for Player #1:

1. Put the black king in the center.
2. Check with a white knight.
3. Check with the other white knight.
4. Fill up all the black king's remaining escape squares with random
pieces.

Then it's "mate", because both knights can't be captured at once.

Player #2 can't prevent any of this.

Larry

If I knew that was your strategy, I could easily prevent it. On
my first turn I'd put one white knight in a corner. That leaves
you only one of the white knights you need. (Not that I'm
disagreeing with the conclusion, only with the proposed method of
ensuring it.)

You're right, sorry. A sample winning sequence for Player #1 is:

Black king - d4, White knight - a8
White knight - b3, any
White rook - e4 or d5 "mate".

Clearly Dgates' "dogpile" strategy wins easily.


Hence, the need to enforce the rule:

"There has to be a possible non-checking position that could
have come right before this checkmate."


At least with that rule, Player One stands a better chance than Player
Two stands without it!

--