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Home > Archive > Chinese chess > January 2005 > Pawn vs advisor endgame question
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Pawn vs advisor endgame question
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| Richard 2005-01-08, 12:46 am |
| I have a question about an endgame depicted in the book "First Syllabus
on XiangQi: Chinese Chess 1" by David Li. For those who own the book,
the position is diagram 11 on page 31, with explanations on pages
30-32.
For those who don't own the book, it's a basic pawn vs advisor endgame.
Red (or white, since it's a black and white book) has a king in its
starting position, and a pawn on the center file just outside the
opponent's palace, on the opponent's 4th rank. Black has his king in
the front corner of his palace, on his 4th file. Black also has an
advisor in its starting position on his 6th file. Those are the only
four pieces on the board.
Here are the full moves:
1. P5+1 K4-1
2. K5+1 K4-1
3. P5.6 A6+5
4. P6.5 A5-6
5. K5.4 K4+1
6. K4+1 K4-1
7. P5.6 K4.5
8. P6+1 A6+5
9. K4.5 K5.6
10. P6.5 stalemate
Li states that 7. ... K4.5 was the wrong move for black, and that he
should have just moved his advisor to the center with A6+5 again, to
threaten the pawn.
It seems that as long as black keeps his king and advisor in the bottom
corners of the palace, white cannot capture the advisor and force mate.
Black just keeps moving his king back and forth with K4+1 and K4-1
whenever the pawn is in the center of the palace. When the pawn tries
to move over to a corner of the palace to reposition for an attack,
black plays A6+5, then moves back with A5-6 on the next move if the
pawn moves back to the center. In other words, black keeps his advisor
out of a position to be captured, and he keeps his king and advisor
from ever being next to each other in such a way that the advisor would
limit the king's movement.
So my question is whether or not a lone pawn can force a win against a
lone advisor. It seems to me from all of this that if black played the
best possible defense, the pawn could not break through and capture the
advisor safely, so the game would end in a draw. My initial reading of
Li's book made me think that this was a forced win for white, since the
example shows white winning, but that's only because black didn't play
the best defense.
So if black defends perfectly, is this a drawn game?
..
Richard "The Fromper" Becker
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| spamtokeith@gmail.com 2005-01-08, 12:46 am |
|
Richard wrote:
quote:
> I have a question about an endgame depicted in the book "First
Syllabus
quote:
> on XiangQi: Chinese Chess 1" by David Li. For those who own the book,
> the position is diagram 11 on page 31, with explanations on pages
> 30-32.
>
Did you look at this this site:
http://lpforth.forthfreak.net/cgi-b...93K54p4999994k4
I think that I entered the position correctly.
-Keith
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| Richard 2005-01-08, 6:46 am |
| spamtokeith@gmail.com wrote:
quote:
> Richard wrote:
> Syllabus
book,[vbcol=seagreen]
>
> Did you look at this this site:
>
> http://lpforth.forthfreak.net/cgi-b...93K54p4999994k4
> I think that I entered the position correctly.
>
> -Keith
Ahh, I see. Once I looked up the instructions to the page, that was
very useful. The database says that this particular position is a draw,
and that pawn vs advisor endgames end in draws most of the time. That
answers my question.
Thanks!
--Richard "The Fromper" Becker
| |
| Richard 2005-01-08, 6:46 am |
| spamtokeith@gmail.com wrote:
quote:
> Richard wrote:
> Syllabus
book,[vbcol=seagreen]
>
> Did you look at this this site:
>
> http://lpforth.forthfreak.net/cgi-b...93K54p4999994k4
> I think that I entered the position correctly.
>
> -Keith
Ahh, I see. Once I looked up the instructions to the page, that was
very useful. The database says that this particular position is a draw,
and that pawn vs advisor endgames end in draws most of the time. And
yes, you did get the position correct.
That answers my question. Thanks!
--Richard "The Fromper" Becker
| |
| David H Li 2005-01-09, 12:45 am |
| Richard Becker, in his query on Pawn-v-Adviser endgame, used an example in
my book, First Syllabus on Xiangqi - Chinese Chess 1, as the basis for his
discussion. This I deeply appreciate. However, perhaps pressed for time,
he gave an incomplete account of what I discussed in the book. To avoid
any misunderstanding, allow me to clarify the issue.
Richard wrote:
quote:
> I have a question about an endgame depicted in the book "First Syllabus
> on XiangQi: Chinese Chess 1" by David Li. For those who own the book,
> the position is diagram 11 on page 31, with explanations on pages
> 30-32.
>
> For those who don't own the book, it's a basic pawn vs advisor endgame.
> Red (or white, since it's a black and white book) has a king in its
> starting position, and a pawn on the center file just outside the
> opponent's palace, on the opponent's 4th rank. Black has his king in
> the front corner of his palace, on his 4th file. Black also has an
> advisor in its starting position on his 6th file. Those are the only
> four pieces on the board.
For this Pawn-vs-Adviser endgame (Case 3 in the book, at pp 29-32), I began
by saying that "with careful play, Black can force a draw; otherwise, a
loss. These are illustrated in Diagrams 10 and 11 (pages 30 and 31)." I
then said "If Black plays unthinkingly by placing both the King and the
Adviser on the same file, Black loses. This is the siutation in Diagram 10
...."
Becker began his query with Diagram 11, where the Adviser is at 6i (not at
4i as in Diagram 10). I then said: "In Diagram 11, White may make the same
first two moves [as in the scenario in Diagram 10]:
quote:
> 1. P5+1 K4-1
> 2. K5+1" [for convenience, Becker's move record is carried over]
I then said: "But, with 4i unoccupied, Black can safely play
quote:
> K4-1"
After saying that White cannot charge down with P5+1, I then said that
"Given this, White applies a new strategy: align the King and Pawn on the
same file as the Black King -- a two-move maneuver: first the Pawn, then
the King:
quote:
> 3. P5.6 [in my book, the lateral move is denoted by =]"
I then said: "With this move, Black must be alert and frustrate White's
plan ...[by playing]
quote:
> A6+5"
I then said, in the book, "With that move, White is forced to move the Pawn
back to file 4, 4 P6=5, and Black returns the Adviser to file 6, 4 ... A5-6
quote:
> 4. P6.5 A5-6"
I then said, in the book: "And a draw is likely to ensue." Immediately
thereafter, I added the following, since my purpose is to show what might
happen to Black for failing to mount the best defense : "However, before
settling for a draw, White may try another maneuver:
quote:
> 5. K5.4 K4+1
> 6. K4+1 K4-1
> 7. P5.6
For Whiite's Move 5, I said that it was "a brilliant move, deserving an
exclamation mark (!)" I also said that "White continues with still another
brilliant move, ... [with] 7 P5=6" These two exclamation marks also appear
in the move record, thus: 5 K5=4! and 7 P5=6!
In the next paragraph, I continued by saying: "As before, Black's most
effective countermeasure is to play 7 ... A6+5. But, if Black, lulled by
White King's having vacated file 5, moves the King to file 5, 5 ... K4=5, a
questionable move (shown with a question mark (?)), all is lost:
quote:
> K4.5
> 8. P6+1 A6+5
> 9. K4.5 K5.6
> 10. P6.5 stalemate" [there is also a ? following 7 ... K4=5]
Becker summarized well with the following:
quote:
> Li states that 7. ... K4.5 was the wrong move for black, and that he
> should have just moved his advisor to the center with A6+5 again, to
> threaten the pawn.
Indeed, I have to rate his summary as brilliant:
quote:
> It seems that as long as black keeps his king and advisor in the bottom
> corners of the palace, white cannot capture the advisor and force mate.
> Black just keeps moving his king back and forth with K4+1 and K4-1
> whenever the pawn is in the center of the palace. When the pawn tries
> to move over to a corner of the palace to reposition for an attack,
> black plays A6+5, then moves back with A5-6 on the next move if the
> pawn moves back to the center. In other words, black keeps his advisor
> out of a position to be captured, and he keeps his king and advisor
> from ever being next to each other in such a way that the advisor would
> limit the king's movement.
He also asked a cogent question:
quote:
> So my question is whether or not a lone pawn can force a win against a
> lone advisor.
However, for clarity as well as for completeness, perhaps, a qualifying
clause is needed: "when the King and the Adviser occupy bottom corners of
the palace" (that is, the position in Diagram 11). Were this clause not
added, the King and the Adviser could be on the same file (the position in
Diagram 10), producing a completely different result. However, in
fairness, Becker has added this qualifying clause in the paragraph
preceding his question, though, adding this clause is preferable, as it
makes the question unambiguous.
quote:
> It seems to me from all of this that if black played the
> best possible defense, the pawn could not break through and capture the
> advisor safely, so the game would end in a draw.
This is indeed so, as I so stated in the book, as quoted above. But I find
Becker's subsequent presentation troublesome:
quote:
> My initial reading of
> Li's book made me think that this was a forced win for white, since the
> example shows white winning, but that's only because black didn't play
> the best defense.
Again, as noted above, my purpose is to show what might happen were Black
to play unthinkingly. The following sentence, appearing at the beginning
of my Case 3 presentation, at page 29 of the book, is worthy of repeating:
"with careful play, Black can force a draw; otherwise, a loss." The
purpose here is not to give a "forced win" to White, as Becker alleged, but
to show, as I said earlier, what might happen if Black does not put up the
best defense (as by falling into White's trap, as here). In short, the
game is for Black to lose or to draw; White's role is passive.
quote:
> So if black defends perfectly, is this a drawn game?
With the clarification given above, the answer to this question is obvious:
a resounding affirmative.
David Li
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| spamtokeith@gmail.com 2005-01-12, 9:45 am |
|
Richard wrote:
quote:
> I have a question about an endgame depicted in the book "First
Syllabus
quote:
> on XiangQi: Chinese Chess 1" by David Li. For those who own the book,
> the position is diagram 11 on page 31, with explanations on pages
> 30-32.
>
Did you look at this this site:
http://lpforth.forthfreak.net/cgi-b...93K54p4999994k4
I think that I entered the position correctly.
-Keith
| |
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| Richard 2005-01-12, 9:45 am |
| spamtokeith@gmail.com wrote:
quote:
> Richard wrote:
> Syllabus
book,[vbcol=seagreen]
>
> Did you look at this this site:
>
> http://lpforth.forthfreak.net/cgi-b...93K54p4999994k4
> I think that I entered the position correctly.
>
> -Keith
Ahh, I see. Once I looked up the instructions to the page, that was
very useful. The database says that this particular position is a draw,
and that pawn vs advisor endgames end in draws most of the time. That
answers my question.
Thanks!
--Richard "The Fromper" Becker
| |
| Richard 2005-01-12, 9:45 am |
| spamtokeith@gmail.com wrote:
quote:
> Richard wrote:
> Syllabus
book,[vbcol=seagreen]
>
> Did you look at this this site:
>
> http://lpforth.forthfreak.net/cgi-b...93K54p4999994k4
> I think that I entered the position correctly.
>
> -Keith
Ahh, I see. Once I looked up the instructions to the page, that was
very useful. The database says that this particular position is a draw,
and that pawn vs advisor endgames end in draws most of the time. And
yes, you did get the position correct.
That answers my question. Thanks!
--Richard "The Fromper" Becker
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