Make the bar point or step up?

[Timothy Chow]

Yet another problem that Stick solved purely from the subject line.

XGID=----BbD-C-A-cDb--b-bbb--A-:0:0:1:11:0:0:0:0:10

Score is X:0 O:0. Unlimited Game
+13-14-15-16-17-18------19-20-21-22-23-24-+
| X O O | | O O O X |
| X O O | | O O O |
| X | | |
| X | | |
| | | |
| |BAR| |
| | | |
| | | X |
| O X | | X |
| O X | | X O X |
| O X X | | X O X |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 142 O: 147 X-O: 0-0
Cube: 1
X to play 11

---
Tim Chow

[Timothy Chow]

XGID=----BbD-C-A-cDb--b-bbb--A-:0:0:1:11:0:0:0:0:10

Score is X:0 O:0. Unlimited Game
+13-14-15-16-17-18------19-20-21-22-23-24-+
| X O O | | O O O X |
| X O O | | O O O |
| X | | |
| X | | |
| | | |
| |BAR| |
| | | |
| | | X |
| O X | | X |
| O X | | X O X |
| O X X | | X O X |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 142 O: 147 X-O: 0-0
Cube: 1
X to play 11

The bar point has diminished value when O has the golden anchor.
But X also has to consider the risk of being attacked if he steps
up. O doesn't have a lot of attackers in position, so XG says that
stepping up is the way to go. But see the variant for comparison.

1. Rollout¹ 24/22 10/8 eq:-0.474
Player: 39.74% (G:6.47% B:0.21%)
Opponent: 60.26% (G:18.38% B:0.35%)
Confidence: ±0.013 (-0.487..-0.461) - [100.0%]

2. Rollout¹ 10/7 8/7 eq:-0.560 (-0.086)
Player: 36.52% (G:5.30% B:0.20%)
Opponent: 63.48% (G:15.27% B:0.35%)
Confidence: ±0.013 (-0.573..-0.547) - [0.0%]

¹ 1296 Games rolled with Variance Reduction.
Dice Seed: 271828
Moves: 3-ply, cube decisions: XG Roller

eXtreme Gammon Version: 2.19.211.pre-release

-------
Variant
-------

XGID=----BbD-C-A-cDa--c-bbb--A-:0:0:1:11:0:0:0:0:10

Score is X:0 O:0. Unlimited Game
+13-14-15-16-17-18------19-20-21-22-23-24-+
| X O O | | O O O X |
| X O | | O O O |

| X O | | |

| X | | |
| | | |
| |BAR| |
| | | |
| | | X |
| O X | | X |
| O X | | X O X |
| O X X | | X O X |
+12-11-10--9--8--7-------6--5--4--3--2--1-+

Pip count X: 142 O: 144 X-O: 0-0

Cube: 1
X to play 11

1. Rollout¹ 10/7 8/7 eq:-0.537
Player: 37.08% (G:5.04% B:0.20%)
Opponent: 62.92% (G:14.91% B:0.31%)
Confidence: ±0.012 (-0.549..-0.525) - [93.4%]

2. Rollout¹ 24/22 10/8 eq:-0.551 (-0.014)
Player: 37.90% (G:5.77% B:0.21%)
Opponent: 62.10% (G:19.48% B:0.27%)
Confidence: ±0.013 (-0.564..-0.538) - [6.6%]

¹ 1296 Games rolled with Variance Reduction.
Dice Seed: 271828
Moves: 3-ply, cube decisions: XG Roller

eXtreme Gammon Version: 2.19.211.pre-release

---
Tim Chow