Robert just posted a double 5s problem, and it just so happens
that the next problem in my queue is also a double 5s problem.

XGID=-BAaB-C-----cC-A-b-cbCb-b-:1:1:1:55:0:0:0:0:10

Score is X:0 O:0. Unlimited Game
+13-14-15-16-17-18------19-20-21-22-23-24-+
| X X O | | O O X O O |
| X O | | O O X O O |
| X | | O X |
| | | |
| | | |
| |BAR| |
| | | |
| | | |
| O | | X | +---+
| O | | X X X | | 2 |
| O | | X X O X X | +---+
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 147 O: 113 X-O: 0-0
Cube: 2, X own cube
X to play 55

---
Tim Chow

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

On Thursday, February 23, 2023 at 3:02:20 PM UTC-5, Timothy Chow wrote:

Robert just posted a double 5s problem, and it just so happens
that the next problem in my queue is also a double 5s problem.

XGID=-BAaB-C-----cC-A-b-cbCb-b-:1:1:1:55:0:0:0:0:10

Score is X:0 O:0. Unlimited Game
+13-14-15-16-17-18------19-20-21-22-23-24-+
| X X O | | O O X O O |
| X O | | O O X O O |
| X | | O X |
| | | |
| | | |
| |BAR| |
| | | |
| | | |
| O | | X | +---+
| O | | X X X | | 2 |
| O | | X X O X X | +---+
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 147 O: 113 X-O: 0-0
Cube: 2, X own cube
X to play 55

---
Tim Chow

Making the 3 point on O's head looks good for immediately building the inner board. AFAICT, any play of the 55 should have that as an immediate goal. It takes away half of O's next roll, and possibly the whole roll (16/36). It leaves 15 rolls that hit
back.
13/8 (3) 15/10 is safer with 6 return shots, brings builders down for the board, but leaves O with freedom right out of the gate. There is only a plan C at that point, hoping to win from a 4-point holding game.
I don't see other plays that don't leave too many blots or reduce contact to a hopeless race.

I'd make the 3 point. There are sufficient chances to recover from one of those 16 hits, have a good board and another shot.

Bob

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

XGID=-BAaB-C-----cC-A-b-cbCb-b-:1:1:1:55:0:0:0:0:10

Score is X:0 O:0. Unlimited Game
+13-14-15-16-17-18------19-20-21-22-23-24-+
| X X O | | O O X O O |
| X O | | O O X O O |
| X | | O X |
| | | |
| | | |
| |BAR| |
| | | |
| | | |
| O | | X | +---+
| O | | X X X | | 2 |
| O | | X X O X X | +---+
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 147 O: 113 X-O: 0-0
Cube: 2, X own cube
X to play 55

Like Robert, I tried the PoH play here, having learned from experience
that I tend to underestimate the strength of putting up an opponent's
checker against a four-point board. XG says that PoH is the DMP play,
but with all those blots and O's four-point board, PoH loses too many
gammons for money.

In the variant, I have weakened O's board, and PoH rolls out on top.

1. Rollout¹ 21/6 15/10 eq:-0.291
Player: 32.59% (G:4.57% B:0.07%)
Opponent: 67.41% (G:9.83% B:0.30%)
Confidence: ±0.006 (-0.296..-0.285) - [100.0%]

2. Rollout¹ 21/16(3) 15/10 eq:-0.363 (-0.073)
Player: 31.63% (G:3.60% B:0.10%)
Opponent: 68.37% (G:14.49% B:0.19%)
Confidence: ±0.006 (-0.369..-0.357) - [0.0%]

3. Rollout¹ 13/3*(2) eq:-0.378 (-0.087)
Player: 34.33% (G:10.28% B:0.10%)
Opponent: 65.67% (G:29.12% B:1.16%)
Confidence: ±0.008 (-0.386..-0.369) - [0.0%]

4. Rollout¹ 15/10 13/8(3) eq:-0.394 (-0.104)
Player: 28.68% (G:3.90% B:0.06%)
Opponent: 71.32% (G:10.17% B:0.22%)
Confidence: ±0.006 (-0.400..-0.389) - [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=-BAaB-C-----cC-A-b-ccCb-a-:1:1:1:55:0:0:0:0:10

Score is X:0 O:0. Unlimited Game
+13-14-15-16-17-18------19-20-21-22-23-24-+
| X X O | | O O X O O |
| X O | | O O X O |
| X | | O O X |
| | | |
| | | |
| |BAR| |
| | | |
| | | |
| O | | X | +---+
| O | | X X X | | 2 |
| O | | X X O X X | +---+
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 147 O: 117 X-O: 0-0
Cube: 2, X own cube
X to play 55

1. Rollout¹ 13/3*(2) eq:-0.128
Player: 40.43% (G:15.24% B:0.23%)
Opponent: 59.57% (G:24.13% B:0.96%)
Confidence: ±0.008 (-0.136..-0.119) - [100.0%]

2. Rollout¹ 21/6 15/10 eq:-0.186 (-0.059)
Player: 35.97% (G:6.79% B:0.10%)
Opponent: 64.03% (G:9.43% B:0.36%)
Confidence: ±0.007 (-0.193..-0.179) - [0.0%]

3. Rollout¹ 21/16(3) 15/10 eq:-0.222 (-0.095)
Player: 35.96% (G:5.10% B:0.12%)
Opponent: 64.04% (G:12.64% B:0.27%)
Confidence: ±0.007 (-0.229..-0.215) - [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

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)