GNU Backgammon Position ID: tncLACCMt5EBMA
Match ID : UQlnAXAAEAAE
+13-14-15-16-17-18------19-20-21-22-23-24-+ O: gnubg
| X O | | O O O O O X | 7 points
| X | | O O O O O X |
| | | O O |
| | | O |
| | | |
v| |BAR| | 11 point match
| | | |
| | | X |
| | | X |
| X X | | X X | Rolled 61
| X X X | | X X O | 2 points
+12-11-10--9--8--7-------6--5--4--3--2--1-+ X: axel (Cube: 2)
Pip counts: O 84, X 145

On 12/22/2022 3:11 PM, Axel Reichert wrote:
> GNU Backgammon Position ID: tncLACCMt5EBMA
> Match ID : UQlnAXAAEAAE
> +13-14-15-16-17-18------19-20-21-22-23-24-+ O: gnubg
> | X O | | O O O O O X | 7 points
> | X | | O O O O O X |
> | | | O O |
> | | | O |
> | | | |
> v| |BAR| | 11 point match
> | | | |
> | | | X |
> | | | X |
> | X X | | X X | Rolled 61
> | X X X | | X X O | 2 points
> +12-11-10--9--8--7-------6--5--4--3--2--1-+ X: axel (Cube: 2)
> Pip counts: O 84, X 145

Was this a double before the roll? Maybe not, but I would have thought
about it. In any case, it's likely to be a double next roll, if nothing
disastrous happens, so I don't want to risk losing that double with a
risky play. 11/5 6/5 for me.

---
Tim Chow

On Thursday, December 22, 2022 at 3:11:26 PM UTC-5, Axel Reichert wrote:
> GNU Backgammon Position ID: tncLACCMt5EBMA
> Match ID : UQlnAXAAEAAE
> +13-14-15-16-17-18------19-20-21-22-23-24-+ O: gnubg
> | X O | | O O O O O X | 7 points
> | X | | O O O O O X |
> | | | O O |
> | | | O |
> | | | |
> v| |BAR| | 11 point match
> | | | |
> | | | X |
> | | | X |
> | X X | | X X | Rolled 61
> | X X X | | X X O | 2 points
> +12-11-10--9--8--7-------6--5--4--3--2--1-+ X: axel (Cube: 2)
> Pip counts: O 84, X 145

Not too fast? 5pt before the dice hit the felt. As for cubing before the roll as Tim mentioned, I wouldn't cube anyone here except XG.

Stick

Axel Reichert <mail@axel-reichert.de> writes:

> GNU Backgammon Position ID: tncLACCMt5EBMA
> Match ID : UQlnAXAAEAAE
> +13-14-15-16-17-18------19-20-21-22-23-24-+ O: gnubg
> | X O | | O O O O O X | 7 points
> | X | | O O O O O X |
> | | | O O |
> | | | O |
> | | | |
> v| |BAR| | 11 point match
> | | | |
> | | | X |
> | | | X |
> | X X | | X X | Rolled 61
> | X X X | | X X O | 2 points
> +12-11-10--9--8--7-------6--5--4--3--2--1-+ X: axel (Cube: 2)
> Pip counts: O 84, X 145

This position was more a psychological problem: Over the board, I first
saw the blot on the bar point, grabbed the back checker and hit. After
all, it cannot be that bad to escape from a five-prime and strengthen
outfield control, especially when behind in the race. As a big fan of
backgammon for idiots (paraphrased from Phil Simborg: "hit, else point,
else cover") I did not look elsewhere and did not notice that the
opponent is likely to crash very soon, making an escape much easier and
safer. But after the hit, X gets gammoned in more than 40 % of his
losses.

In hindsight, with a minimal amount of thinking I would have avoided
this 8-times whopper. Time to subscribe to the Zizka Method

https://backgammoncoaching.com/buy-a-book/

? Maybe. For completeness:

Rolled 61:
1. Rollout 11/5 6/5 Eq.: +0.743
0.585 0.075 0.002 - 0.415 0.179 0.018 CL +0.257 CF +0.743
[0.001 0.001 0.000 - 0.001 0.002 0.000 CL 0.005 CF 0.005]
Truncated cubeful rollout (depth 6) with variance reduction
658 games, Mersenne Twister dice gen. with seed 445148145 and quasi-random dice
Stop when std.errs. are small enough: limit 0.0050 (min. 36 games)
Play: world class 2-ply cubeful prune [world class]
keep the first 0 0-ply moves and up to 8 more moves within equity 0.16
Skip pruning for 1-ply moves.
Cube: 2-ply cubeful prune [world class]
Different evaluations after 2 plies:
Play: 1-ply cubeful
keep the first 0 0-ply moves and up to 8 more moves within equity 0.16
Cube: 2-ply cubeful prune [world class]
2. Rollout 13/7 6/5 Eq.: +0.036 (-0.707)
0.425 0.046 0.001 - 0.575 0.335 0.055 CL -0.282 CF +0.036
[0.001 0.000 0.000 - 0.001 0.002 0.001 CL 0.005 CF 0.004]
Truncated cubeful rollout (depth 6) with variance reduction
964 games, Mersenne Twister dice gen. with seed 445148145 and quasi-random dice
Stop when std.errs. are small enough: limit 0.0050 (min. 36 games)
Play: world class 2-ply cubeful prune [world class]
keep the first 0 0-ply moves and up to 8 more moves within equity 0.16
Skip pruning for 1-ply moves.
Cube: 2-ply cubeful prune [world class]
Different evaluations after 2 plies:
Play: 1-ply cubeful
keep the first 0 0-ply moves and up to 8 more moves within equity 0.16
Cube: 2-ply cubeful prune [world class]
3. Rollout 13/7 11/10 Eq.: -0.038 (-0.781)
0.399 0.042 0.001 - 0.601 0.293 0.035 CL -0.333 CF -0.038
[0.001 0.000 0.000 - 0.001 0.002 0.000 CL 0.005 CF 0.004]
Truncated cubeful rollout (depth 6) with variance reduction
837 games, Mersenne Twister dice gen. with seed 445148145 and quasi-random dice
Stop when std.errs. are small enough: limit 0.0050 (min. 36 games)
Play: world class 2-ply cubeful prune [world class]
keep the first 0 0-ply moves and up to 8 more moves within equity 0.16
Skip pruning for 1-ply moves.
Cube: 2-ply cubeful prune [world class]
Different evaluations after 2 plies:
Play: 1-ply cubeful
keep the first 0 0-ply moves and up to 8 more moves within equity 0.16
Cube: 2-ply cubeful prune [world class]
4. Rollout 13/12 13/7 Eq.: -0.081 (-0.824)
0.383 0.042 0.001 - 0.617 0.281 0.031 CL -0.367 CF -0.081
[0.001 0.000 0.000 - 0.001 0.002 0.001 CL 0.005 CF 0.004]
Truncated cubeful rollout (depth 6) with variance reduction
754 games, Mersenne Twister dice gen. with seed 445148145 and quasi-random dice
Stop when std.errs. are small enough: limit 0.0050 (min. 36 games)
Play: world class 2-ply cubeful prune [world class]
keep the first 0 0-ply moves and up to 8 more moves within equity 0.16
Skip pruning for 1-ply moves.
Cube: 2-ply cubeful prune [world class]
Different evaluations after 2 plies:
Play: 1-ply cubeful
keep the first 0 0-ply moves and up to 8 more moves within equity 0.16
Cube: 2-ply cubeful prune [world class]
5. Rollout 13/12 11/5 Eq.: -0.110 (-0.853)
0.391 0.041 0.001 - 0.609 0.347 0.054 CL -0.385 CF -0.110
[0.001 0.000 0.000 - 0.001 0.001 0.000 CL 0.005 CF 0.003]
Truncated cubeful rollout (depth 6) with variance reduction
1054 games, Mersenne Twister dice gen. with seed 445148145 and quasi-random dice
Stop when std.errs. are small enough: limit 0.0050 (min. 36 games)
Play: world class 2-ply cubeful prune [world class]
keep the first 0 0-ply moves and up to 8 more moves within equity 0.16
Skip pruning for 1-ply moves.
Cube: 2-ply cubeful prune [world class]
Different evaluations after 2 plies:
Play: 1-ply cubeful
keep the first 0 0-ply moves and up to 8 more moves within equity 0.16
Cube: 2-ply cubeful prune [world class]
6. Rollout 24/18* 11/10 Eq.: -0.110 (-0.853)
0.366 0.082 0.005 - 0.634 0.451 0.015 CL -0.193 CF -0.110
[0.001 0.000 0.000 - 0.001 0.001 0.000 CL 0.005 CF 0.003]
Truncated cubeful rollout (depth 6) with variance reduction
1743 games, Mersenne Twister dice gen. with seed 445148145 and quasi-random dice
Stop when std.errs. are small enough: limit 0.0050 (min. 36 games)
Play: world class 2-ply cubeful prune [world class]
keep the first 0 0-ply moves and up to 8 more moves within equity 0.16
Skip pruning for 1-ply moves.
Cube: 2-ply cubeful prune [world class]
Different evaluations after 2 plies:
Play: 1-ply cubeful
keep the first 0 0-ply moves and up to 8 more moves within equity 0.16
Cube: 2-ply cubeful prune [world class]

On 12/22/2022 3:11 PM, Axel Reichert wrote:
> GNU Backgammon Position ID: tncLACCMt5EBMA
> Match ID : UQlnAXAAEAAE
> +13-14-15-16-17-18------19-20-21-22-23-24-+ O: gnubg
> | X O | | O O O O O X | 7 points
> | X | | O O O O O X |
> | | | O O |
> | | | O |
> | | | |
> v| |BAR| | 11 point match
> | | | |
> | | | X |
> | | | X |
> | X X | | X X | Rolled 61
> | X X X | | X X O | 2 points
> +12-11-10--9--8--7-------6--5--4--3--2--1-+ X: axel (Cube: 2)
> Pip counts: O 84, X 145

When in doubt make the five point?

It nicely blocks O's runner most of the time and makes her board crunch.
After the crunch we should be able to waltz our runners around the
board at our leisure.

The hit is tempting, but I'll make the five point.

--
Ah....Clem
The future is fun, the future is fair.

On 12/24/2022 9:36 AM, Axel Reichert wrote:
> This position was more a psychological problem: Over the board, I first
> saw the blot on the bar point, grabbed the back checker and hit.

Especially when I play weaker opponents, I use the semi-joking rule of
thumb, "Leave blots to confuse the opponent." That is, when a safe play
and a bold play look about equally good to me, I'll make the bold play,
because it usually gives the opponent some tricky decisions whether to
hit or not to hit. Making the wrong decision in such positions can cost
a huge amount of equity.

> I did not look elsewhere and did not notice that the
> opponent is likely to crash very soon, making an escape much easier and
> safer. But after the hit, X gets gammoned in more than 40 % of his
> losses.

More to the point, I would say, is that X loses about 60% of the time
instead of about 40% of the time. Breaking anchor and leaving blots
when the opponent has you massively outboarded is typically only a
candidate when your opponent has no checkers back and it's your last
chance to send a checker back, and even then it's not always right.

> In hindsight, with a minimal amount of thinking I would have avoided
> this 8-times whopper. Time to subscribe to the Zizka Method
>
> https://backgammoncoaching.com/buy-a-book/

Have you read this book? I've considered buying it but haven't yet.

---
Tim Chow

Timothy Chow <tchow12000@yahoo.com> writes:

> On 12/24/2022 9:36 AM, Axel Reichert wrote:
> when a safe play and a bold play look about equally good to me, I'll
> make the bold play, because it usually gives the opponent some tricky
> decisions whether to hit or not to hit. Making the wrong decision in
> such positions can cost a huge amount of equity.

A nice one! I use this in the opening, but not as a general guideline.

>> https://backgammoncoaching.com/buy-a-book/
>
> Have you read this book?

No. Neither Dirk Schiemann's tome on theory. But both are on my shopping
list. Have you read Dirk's book?

Best regards

Axel

On 12/26/2022 3:11 AM, Axel Reichert wrote:
> No. Neither Dirk Schiemann's tome on theory. But both are on my shopping
> list. Have you read Dirk's book?

I started reading it and intend to get back to it.

I have been reading Michy's third book, "Back Checker Strategy."
I like it better than his first two books, because there are more
ideas in the third book that I haven't thought about before.

---
Tim Chow