Discussion:
Rolling a prime with 44
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Timothy Chow
2024-01-22 14:38:50 UTC
Permalink
XGID=-aB--CCBBB-A--------bcdbc-:1:-1:1:44:0:0:0:0:10

Score is X:0 O:0. Unlimited Game
+13-14-15-16-17-18------19-20-21-22-23-24-+
| | | O O O O O | +---+
| | | O O O O O | | 2 |
| | | O O O | +---+
| | | O |
| | | |
| |BAR| |
| | | |
| | | |
| | | X X |
| X X X | | X X X |
| X X X X | | X X X O |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 96 O: 65 X-O: 0-0
Cube: 2, O own cube
X to play 44

---
Tim Chow
ah...Clem
2024-01-23 17:29:16 UTC
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Post by Timothy Chow
XGID=-aB--CCBBB-A--------bcdbc-:1:-1:1:44:0:0:0:0:10
Score is X:0 O:0. Unlimited Game
 +13-14-15-16-17-18------19-20-21-22-23-24-+
 |                  |   |    O  O  O  O  O | +---+
 |                  |   |    O  O  O  O  O | | 2 |
 |                  |   |       O  O     O | +---+
 |                  |   |          O       |
 |                  |   |                  |
 |                  |BAR|                  |
 |                  |   |                  |
 |                  |   |                  |
 |                  |   | X  X             |
 |          X  X  X |   | X  X        X    |
 |    X     X  X  X |   | X  X        X  O |
 +12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count  X: 96  O: 65 X-O: 0-0
Cube: 2, O own cube
X to play 44
Making the four point seems obvious as does keeping the bar point. X
will be down by 15 pips after this play so don't give O sixes to escape
and cash.

I don't think hitting loose is the right idea - it just gives her two
more rolls to step up to where she can see daylight. Pointing on her
head also seems to accomplish little - we want her on to stay on the ace
point.

So, 8/4(2) 11/7 6/2. Hope she doesn't roll a 52.
Timothy Chow
2024-01-25 14:20:47 UTC
Permalink
XGID=-aB--CCBBB-A--------bcdbc-:1:-1:1:44:0:0:0:0:10

Score is X:0 O:0. Unlimited Game
+13-14-15-16-17-18------19-20-21-22-23-24-+
| | | O O O O O | +---+
| | | O O O O O | | 2 |
| | | O O O | +---+
| | | O |
| | | |
| |BAR| |
| | | |
| | | |
| | | X X |
| X X X | | X X X |
| X X X X | | X X X O |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 96 O: 65 X-O: 0-0
Cube: 2, O own cube
X to play 44

As ah...clem said, 8/4(2) is pretty obvious. For the remaining two 4's,
XG recommends slotting with 11/3. This is great when it works, but is
it too bold? If O had a closed board (see variant below) then XG would
shy away from the slot, but even with a five-point board, XG judges
that the risk is worth it. Part of what one has to consider is that X
is still behind in the pip count, and so will be losing if he plays
11/7 9/5 8/4(2) and if O then escapes with a roll of 52.

1. Rollout¹ 11/3 8/4(2) eq:+0.586
Player: 80.35% (G:3.80% B:0.09%)
Opponent: 19.65% (G:1.60% B:0.01%)
Confidence: ±0.003 (+0.583..+0.590) - [100.0%]

2. Rollout¹ 11/7 9/5 8/4(2) eq:+0.514 (-0.073)
Player: 78.11% (G:2.50% B:0.06%)
Opponent: 21.89% (G:0.55% B:0.00%)
Confidence: ±0.003 (+0.510..+0.517) - [0.0%]

3. Rollout¹ 11/7 8/4(2) 5/1* eq:+0.510 (-0.076)
Player: 77.58% (G:3.66% B:0.09%)
Opponent: 22.42% (G:1.33% B:0.01%)
Confidence: ±0.004 (+0.506..+0.514) - [0.0%]

4. Rollout¹ 11/7 8/4(2) 6/2 eq:+0.492 (-0.095)
Player: 77.41% (G:2.43% B:0.05%)
Opponent: 22.59% (G:0.93% B:0.01%)
Confidence: ±0.004 (+0.487..+0.496) - [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=-aB--CCBBB-A-------bbcbbc-:1:-1:1:44:0:0:0:0:10

Score is X:0 O:0. Unlimited Game
+13-14-15-16-17-18------19-20-21-22-23-24-+
| | | O O O O O O | +---+
| | | O O O O O O | | 2 |
| | | O O | +---+
| | | |
| | | |
| |BAR| |
| | | |
| | | |
| | | X X |
| X X X | | X X X |
| X X X X | | X X X O |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 96 O: 71 X-O: 0-0
Cube: 2, O own cube
X to play 44

1. Rollout¹ 11/7 9/5 8/4(2) eq:+0.514
Player: 77.53% (G:2.53% B:0.06%)
Opponent: 22.47% (G:0.80% B:0.01%)
Confidence: ±0.004 (+0.510..+0.518) - [100.0%]

2. Rollout¹ 11/3 8/4(2) eq:+0.493 (-0.021)
Player: 75.78% (G:3.74% B:0.10%)
Opponent: 24.22% (G:2.55% B:0.01%)
Confidence: ±0.004 (+0.489..+0.497) - [0.0%]

3. Rollout¹ 11/7 8/4(2) 6/2 eq:+0.484 (-0.030)
Player: 77.02% (G:2.42% B:0.05%)
Opponent: 22.98% (G:1.17% B:0.02%)
Confidence: ±0.005 (+0.479..+0.489) - [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

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