Why don't you know the answer to this quiz?

[peps...@gmail.com]

This is a very standard opening position.
IMO, "knowing the answer" means not only being confident in your
response, but knowing how marginal or clear the actions are.
Obviously, the difference between a 0.999 take and a 1.001
isn't significant and there's guesswork to such evals so if it is ultra-marginal
and you know this, then you do know the position, and your take/pass
coin toss is besides the point.

Paul

XGID=-a----E-C-a-eD---bAd-b--AA:0:0:-1:00:0:2:3:0:10
X:eXtremeGammon O:Daniel

Score is X:2 O:0. Unlimited Game, Jacoby Beaver
+13-14-15-16-17-18------19-20-21-22-23-24-+
| X X O | | O X |
| X O | | O |
| X O | | O |
| X | | O |
| X | | O |
| |BAR| |
| | O | |
| O | | X |
| O | | X |
| O X | | X X |
| O X O | | X X O |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 152 O: 173 X-O: 2-0
Cube: 1
X on roll, cube action

[Timothy Chow]

On 9/4/2021 10:18 AM, peps...@gmail.com wrote:
> XGID=-a----E-C-a-eD---bAd-b--AA:0:0:-1:00:0:2:3:0:10
> X:eXtremeGammon O:Daniel
>
> Score is X:2 O:0. Unlimited Game, Jacoby Beaver
> +13-14-15-16-17-18------19-20-21-22-23-24-+
> | X X O | | O X |
> | X O | | O |
> | X O | | O |
> | X | | O |
> | X | | O |
> | |BAR| |
> | | O | |
> | O | | X |
> | O | | X |
> | O X | | X X |
> | O X O | | X X O |
> +12-11-10--9--8--7-------6--5--4--3--2--1-+
> Pip count X: 152 O: 173 X-O: 2-0
> Cube: 1
> X on roll, cube action

Stick would want you to write 42P-63S-63R-F-C, whatever that means.

X is already up 20 pips in the race. He has made his 4pt and has
mostly escaped one of his back checkers. O has, in effect, moved
backwards 6 pips from the start of the game. This has to be a big
double and I'm not sure about the take. Normally if the blitzer
has only 8 checkers in the zone and only one new home-board point
made then it's a clear take, but I've been burned before by not
giving enough weight to X's advantages in this sort of position.
I'll still say D/T though.

---
Tim Chow

[peps...@gmail.com]

Good analysis.
I (correctly) took but got dinged for it in the analysis -- something like 1.04,
I think.
However, when I did a full rollout, it rolled out to a 0.94 take.
It's still quite a bit closer than I thought.
I (wrongly) saw the take as being very clear.

Unfortunately, I didn't save the rollout.

Paul

[Timothy Chow]

On 9/5/2021 5:41 AM, peps...@gmail.com wrote:
> Good analysis.
> I (correctly) took but got dinged for it in the analysis -- something like 1.04,
> I think.
> However, when I did a full rollout, it rolled out to a 0.94 take.
> It's still quite a bit closer than I thought.
> I (wrongly) saw the take as being very clear.
>
> Unfortunately, I didn't save the rollout.

Just now, I did a rollout, but it doesn't confirm your claim
of a 0.94 take.

XGID=-a----E-C-a-eD---bAd-b--AA:0:0:-1:00:0:0:3:0:10

X:Player 1 O:Player 2
Score is X:0 O:0. Unlimited Game, Jacoby Beaver
+12-11-10--9--8--7-------6--5--4--3--2--1-+
| X O X | | O O X |
| X O | | O O |
| X | | O |
| X | | O |
| | X | |
| |BAR| |

| O | | X |
| O | | X |
| O X | | X |

| O X | | X |
| O O X | | X O |
+13-14-15-16-17-18------19-20-21-22-23-24-+
Pip count X: 173 O: 152 X-O: 0-0
Cube: 1
O on roll, cube action

Analyzed in Rollout
No double
Player Winning Chances: 68.73% (G:28.61% B:1.83%)
Opponent Winning Chances: 31.27% (G:6.38% B:0.26%)
Double/Take
Player Winning Chances: 68.50% (G:30.86% B:1.89%)
Opponent Winning Chances: 31.50% (G:6.85% B:0.30%)

Cubeful Equities:
No double: +0.849 (-0.151)
Double/Take: +1.009 (+0.009)
Double/Pass: +1.000

Best Cube action: Double / Pass

Rollout:
1296 Games rolled with Variance Reduction.
Dice Seed: 271828
Moves: 3-ply, cube decisions: XG Roller
Confidence No Double: ± 0.012 (+0.837..+0.861)
Confidence Double: ± 0.019 (+0.990..+1.028)

eXtreme Gammon Version: 2.19.207.pre-release

---
Tim Chow

[peps...@gmail.com]

Hi Tim,

Thanks for this.
Not sure what went wrong on my end.
Since I didn't save the rollout, errors (by me) were always likely.

Paul