XGID=---B-EEB----A--------ad---:1:1:1:22:0:0:0:0:10
X:Player 1 O:Player 2
Score is X:0 O:0. Unlimited Game
+13-14-15-16-17-18------19-20-21-22-23-24-+
| | | O O |
| | | O |
| | | O |
| | | O |
| | | |
| |BAR| |
| | | X X |
| | | X X |
| | | X X | +---+
| X | | X X X | | 2 |
| X X | | X X X | +---+
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 87 O: 16 X-O: 0-0
Cube: 2, X own cube
X to play 22
---
Tim Chow
On Tuesday, April 5, 2022 at 1:57:40 PM UTC+1, Tim Chow wrote:
XGID=---B-EEB----A--------ad---:1:1:1:22:0:0:0:0:10
X:Player 1 O:Player 2
Score is X:0 O:0. Unlimited Game +13-14-15-16-17-18------19-20-21-22-23-24-+
| | | O O |
| | | O |
| | | O |
| | | O |
| | | |
| |BAR| |
| | | X X |
| | | X X |
| | | X X | +---+
| X | | X X X | | 2 |
| X X | | X X X | +---+
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 87 O: 16 X-O: 0-0
Cube: 2, X own cube
X to play 22
---Perhaps not the hardest Gruntyization you've ever set.
Tim Chow
I think a good strategy is to maximise our probability of bearing off in two. (In other words, bearing off on the next roll after this 22).
12/6 7/5 definitely comes into consideration. This gives us a gammon save with any 6, 5 or 3 -- 27.
We can also add the two Gruntyizations -- 11 and 22 for a 29/36 probability.
That might be tough to beat.
It looks to me like any other play will give a bad ace. So I'm sticking with my 29/36 problem.
So what's the moral of this story?
It's better to Gruntyize than to temporise -- that's my lesson learned.
Paul
On Tuesday, April 5, 2022 at 7:21:59 PM UTC+1, peps...@gmail.com wrote:A riddle:
On Tuesday, April 5, 2022 at 1:57:40 PM UTC+1, Tim Chow wrote:
XGID=---B-EEB----A--------ad---:1:1:1:22:0:0:0:0:10
X:Player 1 O:Player 2
Score is X:0 O:0. Unlimited Game +13-14-15-16-17-18------19-20-21-22-23-24-+
| | | O O |
| | | O |
| | | O |
| | | O |
| | | |
| |BAR| |
| | | X X |
| | | X X |
| | | X X | +---+
| X | | X X X | | 2 |
| X X | | X X X | +---+
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 87 O: 16 X-O: 0-0
Cube: 2, X own cube
X to play 22
---Perhaps not the hardest Gruntyization you've ever set.
Tim Chow
I think a good strategy is to maximise our probability of bearing off in two.
(In other words, bearing off on the next roll after this 22).
12/6 7/5 definitely comes into consideration. This gives us a gammon save with any 6, 5 or 3 -- 27.
We can also add the two Gruntyizations -- 11 and 22 for a 29/36 probability.
That might be tough to beat.
It looks to me like any other play will give a bad ace. So I'm sticking with my 29/36 problem.
So what's the moral of this story?
It's better to Gruntyize than to temporise -- that's my lesson learned.
PaulI mean "29/36 probability" (not problem).
Paul
XGID=---B-EEB----A--------ad---:1:1:1:22:0:0:0:0:10In my experience, this is a very common concept in chess writing.
X:Player 1 O:Player 2
Score is X:0 O:0. Unlimited Game
+13-14-15-16-17-18------19-20-21-22-23-24-+
| | | O O |
| | | O |
| | | O |
| | | O |
| | | |
| |BAR| |
| | | X X |
| | | X X |
| | | X X | +---+
| X | | X X X | | 2 |
| X X | | X X X | +---+
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 87 O: 16 X-O: 0-0
Cube: 2, X own cube
X to play 22
In "John Nunn's Chess Puzzle Book," he has a section called, "Find
the Wrong Move." Unlike most puzzles, in which the goal is to find
the right move, the goal in these puzzles is to guess what plausible
but wrong move was made OTB.
Here, the "obvious" 12/6 7/5 is correct. But somehow I fixated on
the gap on my 4pt, and played 12/8 7/5(2) to give myself a good 4.
It's true that after 12/6 7/5, I could roll 44 several times in a
row and get gammoned, but this is a rare event, and guarding against
a bad ace is a higher priority.
1. Rollout¹ 12/6 7/5 eq:-1.041
Player: 0.00% (G:0.00% B:0.00%)
Opponent: 100.00% (G:4.06% B:0.00%)
Confidence: ±0.000 (-1.041..-1.041) - [100.0%]
2. Rollout¹ 12/8 7/5(2) eq:-1.075 (-0.034)
Player: 0.00% (G:0.00% B:0.00%)
Opponent: 100.00% (G:7.46% B:0.00%)
Confidence: ±0.000 (-1.075..-1.075) - [0.0%]
3. Rollout¹ 12/10 7/5(2) 3/1 eq:-1.086 (-0.046)
Player: 0.00% (G:0.00% B:0.00%)
Opponent: 100.00% (G:8.65% B:0.00%)
Confidence: ±0.000 (-1.087..-1.086) - [0.0%]
¹ 1296 Games rolled with Variance Reduction.
Dice Seed: 271828
Moves and cube decisions: XG Roller++
Search interval: Gigantic
eXtreme Gammon Version: 2.19.207.pre-release
And I've seen many problems in newspaper or magazine articles with exactly the
same goal. However, usually, these problems are presented as a dual:
A) Find the wrong move. B) Find the way your opponent should reply if you do make the wrong move.
In fact, a non-dual which focused solely on A without B seems a bit implausible.
And not really possible. If you don't do B, you can't explain why your answer to A is indeed wrong.
It's possible that John Nunn popularised the concept, I suppose.
On 4/14/2022 2:08 PM, peps...@gmail.com wrote:
And I've seen many problems in newspaper or magazine articles with exactly theYes, that's what Nunn asks the reader to do.
same goal. However, usually, these problems are presented as a dual:
A) Find the wrong move. B) Find the way your opponent should reply if you do make the wrong move.
In fact, a non-dual which focused solely on A without B seems a bit implausible.
And not really possible. If you don't do B, you can't explain why your answer to A is indeed wrong.
And there are also tasks that the reader asks Nunn to do (at least one reader, anyway).
1) Write a book on Q + P vs Q endings -- the lack of such a book is a marked gap in his
series on five-piece endings.
2) Write a book on selfmates -- someone needs to.
XGID=---B-EEB----A--------ad---:1:1:1:22:0:0:0:0:10
X:Player 1 O:Player 2
Score is X:0 O:0. Unlimited Game
+13-14-15-16-17-18------19-20-21-22-23-24-+
| | | O O |
| | | O |
| | | O |
| | | O |
| | | |
| |BAR| |
| | | X X |
| | | X X |
| | | X X | +---+
| X | | X X X | | 2 |
| X X | | X X X | +---+
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 87 O: 16 X-O: 0-0
Cube: 2, X own cube
X to play 22
In "John Nunn's Chess Puzzle Book," he has a section called, "Find
the Wrong Move." Unlike most puzzles, in which the goal is to find
the right move, the goal in these puzzles is to guess what plausible
but wrong move was made OTB.
Here, the "obvious" 12/6 7/5 is correct. But somehow I fixated on
the gap on my 4pt, and played 12/8 7/5(2) to give myself a good 4.
It's true that after 12/6 7/5, I could roll 44 several times in a
row and get gammoned, but this is a rare event, and guarding against
a bad ace is a higher priority.
1. Rollout¹ 12/6 7/5 eq:-1.041
Player: 0.00% (G:0.00% B:0.00%)
Opponent: 100.00% (G:4.06% B:0.00%)
Confidence: ±0.000 (-1.041..-1.041) - [100.0%]
2. Rollout¹ 12/8 7/5(2) eq:-1.075 (-0.034)
Player: 0.00% (G:0.00% B:0.00%)
Opponent: 100.00% (G:7.46% B:0.00%)
Confidence: ±0.000 (-1.075..-1.075) - [0.0%]
3. Rollout¹ 12/10 7/5(2) 3/1 eq:-1.086 (-0.046)
Player: 0.00% (G:0.00% B:0.00%)
Opponent: 100.00% (G:8.65% B:0.00%)
Confidence: ±0.000 (-1.087..-1.086) - [0.0%]
¹ 1296 Games rolled with Variance Reduction.
Dice Seed: 271828
Moves and cube decisions: XG Roller++
Search interval: Gigantic
eXtreme Gammon Version: 2.19.207.pre-release
---
Tim Chow
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