Hello,
GNU Backgammon Position ID: DwAA4L+jQAAAAA
Match ID : UYlmAYAAMAAE
+13-14-15-16-17-18------19-20-21-22-23-24-+ O: gnubg
| | | O | OOO 8 points
| | | O | OO
| | | O | OO
| | | O | OO
| | | | OO
v| |BAR| | 11 point match
| | | 9 |
| | | X |
| | | X X |
| | | X X | Rolled 51
| X | | X X X X | 6 points
+12-11-10--9--8--7-------6--5--4--3--2--1-+ X: axel (Cube: 2)
an easy one, but I overlooked it over the board in auto-pilot mode. No rollout needed for the correct solution, but once I saw it after
switching off my reptile brain, it made me smile, because it involves
two counter-intuitive things.
Hello,Very similar to Puzzle 4 here:
GNU Backgammon Position ID: DwAA4L+jQAAAAA
Match ID : UYlmAYAAMAAE
+13-14-15-16-17-18------19-20-21-22-23-24-+ O: gnubg
| | | O | OOO 8 points
| | | O | OO
| | | O | OO
| | | O | OO
| | | | OO
v| |BAR| | 11 point match
| | | 9 |
| | | X |
| | | X X |
| | | X X | Rolled 51
| X | | X X X X | 6 points
+12-11-10--9--8--7-------6--5--4--3--2--1-+ X: axel (Cube: 2)
an easy one, but I overlooked it over the board in auto-pilot mode. No rollout needed for the correct solution, but once I saw it after
switching off my reptile brain, it made me smile, because it involves
two counter-intuitive things.
Hello,
GNU Backgammon Position ID: DwAA4L+jQAAAAA
Match ID : UYlmAYAAMAAE
+13-14-15-16-17-18------19-20-21-22-23-24-+ O: gnubg
| | | O | OOO 8 points
| | | O | OO
| | | O | OO
| | | O | OO
| | | | OO
v| |BAR| | 11 point match
| | | 9 |
| | | X |
| | | X X |
| | | X X | Rolled 51
| X | | X X X X | 6 points
+12-11-10--9--8--7-------6--5--4--3--2--1-+ X: axel (Cube: 2)
an easy one, but I overlooked it over the board in auto-pilot mode. No rollout needed for the correct solution, but once I saw it after
switching off my reptile brain, it made me smile, because it involves
two counter-intuitive things.
Best regards
Axel
12/7 2/1 is the uniquely correct play
"peps...@gmail.com" <peps...@gmail.com> writes:
12/7 2/1 is the uniquely correct play
Yes, and the two counter-intuitive properties
are to refrain from changing the quadrant
and instead to pile further checkers onto
the already high ace-point stack.
Hello,
GNU Backgammon Position ID: DwAA4L+jQAAAAA
Match ID : UYlmAYAAMAAE
+13-14-15-16-17-18------19-20-21-22-23-24-+ O: gnubg
| | | O | OOO 8 points
| | | O | OO
| | | O | OO
| | | O | OO
| | | | OO
v| |BAR| | 11 point match
| | | 9 |
| | | X |
| | | X X |
| | | X X | Rolled 51
| X | | X X X X | 6 points
+12-11-10--9--8--7-------6--5--4--3--2--1-+ X: axel (Cube: 2)
an easy one, but I overlooked it over the board in auto-pilot mode. No rollout needed for the correct solution, but once I saw it after
switching off my reptile brain, it made me smile, because it involves
two counter-intuitive things.
Best regards
Axel
On November 19, 2022 at 7:06:24 AM UTC-7, Axel Reichert wrote:
"peps...@gmail.com" <peps...@gmail.com> writes:
12/7 2/1 is the uniquely correct play
Yes, and the two counter-intuitive propertiesI mostly skip position discussing threads as
are to refrain from changing the quadrant
and instead to pile further checkers onto
the already high ace-point stack.
uninteresting but having once had, way back
when, an interest in our "three brains", your
catchy title was irresistible and I'm glad it was.
At my usual playing pace, it would be easy to
see 12/7 takes care of 43, 34 (with 33, 44 not
being problems) but I would play 5/4 not seing
the newly created 53 gap so easily, even after
being tipped off that this is a tricky position.
I (like most people) would only see the 2/1 if
the stakes were high enough to play it slowly
like chess, by considering all possibilities one
by one (as Paul has done and illustrated).
From now on, I think I'll read all threads with
the words "reptilian brain" in the title. :))
MK
On Saturday, November 19, 2022 at 11:30:11 PM UTC, MK wrote:
"peps...@gmail.com" <peps...@gmail.com> writes:
12/7 2/1 is the uniquely correct play
I (like most people) would only see the 2/1 if
the stakes were high enough to play it slowly
like chess, by considering all possibilities one
by one (as Paul has done and illustrated).
Good post.
A small addition is that just as 5/4 makes 53 a
problem roll, 6/5 makes 33 a problem roll so we
can't do that either, making the solution unique.
I always save these straightforward yet don't fall asleep on me save the gammon type plays. I have accumulated quite the collection of naturally occurring positions.
On 11/20/2022 5:38 AM, Stick Rice wrote:
I always save these straightforward yet
don't fall asleep on me save the gammon
type plays. I have accumulated quite the
collection of naturally occurring positions.
I have a bunch of these too, although I don't
usually save the ones where the opponent
has only two rolls left.
Here's one, chosen more or less at random
from my files.
XGID=--BBBBD-A---A-A--------bc-:1:1:1:61:0:0:0:0:10
"Save the gammon type plays" mostly occur
very late in games, thus are limited enough in
numbers, thus almost all are likely to "occur
naturally", unless you limit yourself to define
naturally as only in "bot vs bot" games.
I have a bunch of these too, although I don't
usually save the ones where the opponent
has only two rolls left.
Why not? There are too many of them? They
don't matter as much as when there are three
rolls left? Four rolls left? Fifteen rolls left?
Here's one, chosen more or less at random
from my files.
XGID=--BBBBD-A---A-A--------bc-:1:1:1:61:0:0:0:0:10
I fail to see any relevance of this position to
Axel's point. Maybe it's there but I can't see it.
Can you explain?
In all levels, your preferred bot XG's first choice
is 12/6 8/7 which is one of the right moves and
thus everything else after that is moot.
The other right move 12/6 2/1 is XG's third best
move.
On 11/21/2022 6:28 AM, MK wrote:
"Save the gammon type plays" mostly occur
very late in games, thus are limited enough in
numbers, thus almost all are likely to "occur
naturally", unless you limit yourself to define
naturally as only in "bot vs bot" games.
I think Stick meant that one can contrive such
positions that never arose in an actual game.
Such a contrived position would not be
"naturally occurring."
I have a bunch of these too, although I don't
usually save the ones where the opponent
has only two rolls left.
Why not? .....
They're too easy to figure out.
XGID=--BBBBD-A---A-A--------bc-:1:1:1:61:0:0:0:0:10
I fail to see any relevance of this position to
Axel's point. Maybe it's there but I can't see it.
Can you explain?
When I'm on auto-pilot, I usually move the
checker in my opponent's outfield rather than
my own outfield, so in this position, my "reptile
brain" would play 12/6 14/13.
The other right move 12/6 2/1 is XG's third
best move.
I don't understand why you describe 12/6 2/1
as "the other right move."
The other right move 12/6 2/1 is XG's third
best move.
I don't understand why you describe 12/6 2/1
as "the other right move."
Since I didn't find it unusual, I thought that there
may be something hidden deeper. So, I imported
the XGID to see how the bot played. Your move,
which is also the bot's second choice, creates an
additional anti-joker of a 21 followed by a 53 but
the bot's third choice 12/6 2/1 doesn't.
Since the bot's first choice is one of the two right
moves, it doesn't change the outcome but how a
bot can miss what even I could see...? That why I
said a lizard must have sneaked into XG's AI brain. :)
But 12/6 2/1 is certainly a bad move and not right.
If I play 12/6 2/1 (and the opponent doesn't roll
doublets) then on my next turn, if I roll 61 51 41 31
or 21, then I can't get two crossovers. That forces
me to roll doublets after that to get off the gammon.
On November 24, 2022 at 5:00:41 PM UTC-7, Tim Chow wrote:
But 12/6 2/1 is certainly a bad move and not right.
If I play 12/6 2/1 (and the opponent doesn't roll
doublets) then on my next turn, if I roll 61 51 41 31
or 21, then I can't get two crossovers. That forces
me to roll doublets after that to get off the gammon.
It's the same if you roll a lone 1 in the other two cases
also but since I had pointed out the 53 followed by 21,
I first wanted to double check that. Guess what? A 21
followed by 53 plays differently... :o)
On 11/24/2022 10:26 PM, MK wrote:
It's the same if you roll a lone 1 in the other two cases
also but since I had pointed out the 53 followed by 21,
I first wanted to double check that. Guess what? A 21
followed by 53 plays differently... :o)
I don't quite understand what you're saying here.
Are you now agreeing that the computer is correct
when it says that 12/6 2/1 is third best, and that
12/6 2/1 is not a correct move?
After playing 12/6 8/7
------------------------
66 55 44 save immediately
If first roll > 7 (i.e. 65 64 63 62 56 54 53 46 45 36 35
33 26 22), all next rolls save including lone 1s
If first roll <= 7 and next roll has a lone 1, it loses
If first roll has a 1 and is 61 16, next roll needs any
doubles (i.e. 11 22 33 44 55 66)
On 11/25/2022 4:45 PM, MK wrote:
After playing 12/6 8/7
.....
If first roll <= 7 and next roll has a lone 1, it loses
If first roll has a 1 and is 61 16, next roll needs
any doubles (i.e. 11 22 33 44 55 66)
We have just one checker outside our board,
on the 8pt, so all kinds of non-doubles will
get us off the gammon---even 32 will work.
Let's ignore 12/6 8/7 and concentrate on the
12/6 14/13 and 12/6 2/1. Do you guys agree
with me that XG got them in the wrong order?
On 11/26/2022 4:24 PM, MK wrote:
Let's ignore 12/6 8/7 and concentrate on the
12/6 14/13 and 12/6 2/1. Do you guys agree
with me that XG got them in the wrong order?
There are some other differences between
the two plays but this is the main issue.
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