Which hit?

[Timothy Chow]

XGID=-----aE-C-a-cD--bcBe-----A:0:0:1:44:0:0:0:0:10

Score is X:0 O:0. Unlimited Game
+13-14-15-16-17-18------19-20-21-22-23-24-+
| X O O X | | O |
| X O O X | | O |
| X O | | O |
| X | | O |
| | X | O |
| |BAR| |
| | | X |
| | | X |
| O X | | X |
| O X | | X |
| O O X | | X O |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 167 O: 146 X-O: 0-0
Cube: 1
X to play 44

---
Tim Chow

[Robert Zimmerman]

I like hitting the blot on 5. It leaves about twice as many shots as hitting on 10 (O might make the 5 point rather than hit after the latter play). But it doesn't afford O the chance to make the 5 point. And if we're fortunate enough to not be hit, which in itself is not so problematic given O's wide open board and our preserved bar point, then we're in a great position offensively. The other problem with hitting the blot on 10 is that even if your blots are left alone by O, the clean up will not be easy or constructive.

Bar/21 13/5 13/9

Bob

[Timothy Chow]

XGID=-----aE-C-a-cD--bcBe-----A:0:0:1:44:0:0:0:0:10

Score is X:0 O:0. Unlimited Game
+13-14-15-16-17-18------19-20-21-22-23-24-+
| X O O X | | O |
| X O O X | | O |
| X O | | O |
| X | | O |
| | X | O |
| |BAR| |
| | | X |
| | | X |
| O X | | X |
| O X | | X |
| O O X | | X O |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 167 O: 146 X-O: 0-0
Cube: 1
X to play 44

Like Bob, I hit on the 5pt. When to hit in my outer board versus when
to hit in my inner board is something I'm still trying to puzzle out.
Hitting in the outer board gains more pips, sends another checker back,
and typically gives fewer return shots. Hitting in the inner board
starts to make that point myself and prevents the opponent from
anchoring. In this position, my bar-point anchor was an asset that I
didn't want to give up, but XG prefers that to 13/9 13/5*. Not sure I
fully understand this one; see also the variant below.

1. Rollout¹ Bar/21 18/14 18/10* eq:-0.168
Player: 46.28% (G:10.12% B:0.44%)
Opponent: 53.72% (G:14.73% B:0.62%)
Confidence: ±0.014 (-0.182..-0.154) - [100.0%]

2. Rollout¹ Bar/21 13/9 13/5* eq:-0.246 (-0.078)
Player: 43.84% (G:10.73% B:0.36%)
Opponent: 56.16% (G:14.33% B:0.63%)
Confidence: ±0.016 (-0.262..-0.230) - [0.0%]

3. Rollout¹ Bar/21 18/10* 10/6 eq:-0.262 (-0.094)
Player: 44.14% (G:8.75% B:0.39%)
Opponent: 55.86% (G:15.09% B:0.53%)
Confidence: ±0.013 (-0.275..-0.250) - [0.0%]

4. Rollout¹ Bar/21 13/9(2) 8/4 eq:-0.265 (-0.097)
Player: 42.56% (G:8.46% B:0.29%)
Opponent: 57.44% (G:9.38% B:0.37%)
Confidence: ±0.012 (-0.277..-0.253) - [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=-----aD-C-a-dE--bbBe-----A:0:0:1:44:0:0:0:0:10

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

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

| |BAR| |
| | | |
| O | | X |

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

Pip count X: 174 O: 151 X-O: 0-0

Cube: 1
X to play 44

1. Rollout¹ Bar/21 18/14 18/10* eq:-0.138
Player: 46.98% (G:9.74% B:0.48%)
Opponent: 53.02% (G:14.48% B:0.62%)
Confidence: ±0.015 (-0.153..-0.123) - [93.8%]

2. Rollout¹ Bar/21 13/9 13/5* eq:-0.155 (-0.017)
Player: 46.25% (G:11.25% B:0.41%)
Opponent: 53.75% (G:13.83% B:0.58%)
Confidence: ±0.014 (-0.169..-0.140) - [6.2%]

3. Rollout¹ Bar/21 13/9(3) eq:-0.171 (-0.033)
Player: 44.76% (G:8.67% B:0.32%)
Opponent: 55.24% (G:8.40% B:0.32%)
Confidence: ±0.013 (-0.184..-0.158) - [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

---
Tim Chow

[Robert Zimmerman]

I'll hazard a guess. Maybe the idea, which I read often, is that given two positions that seem to be equivalent in terms of risk, you should prefer the more offensive play. I think it's easy to be fooled into thinking that hitting on the 5 point is more offensive in trying to keep O off of there, but in fact, O is going to hit you with a five rather than anchor up for most rolls with a 5. And if O does anchor, that's a more defensive stance leaving you to play offense.
The variant you created removes an attacking checker from the five point which weakens the offensive idea.

Just spitballing.

Bob

[Robert Zimmerman]

I should add that taking down the defensive bar point is thematic.
Bob