An unexpected moment to roll boxcars

Discussion:

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Tim Chow

2016-09-15 01:58:34 UTC

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Bradley K. Sherman

2016-09-15 02:14:18 UTC

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Post by Tim Chow
Score is X:0 O:0. Unlimited Game
+13-14-15-16-17-18------19-20-21-22-23-24-+
| O | | O O O X X |
| O | | O O O X |
| | | O O |
| | | |
| | | |
| |BAR| |
| | | |
| | | X |
| | | X X | +---+
| O | | X X X X | | 2 |
| O O O O | | X X X X X | +---+
+12-11-10--9--8--7-------6--5--4--3--2--1-+
X:114 O:126, X to play 66

23/11*,22/16(2)

--bks

BlueDice

2016-09-15 08:50:51 UTC

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Post by Tim Chow
XGID=-ACB-BD-a-aab-----bcbcBA--:1:1:1:66:0:0:0:0:10
X:Player 1 O:Player 2
Score is X:0 O:0. Unlimited Game
+13-14-15-16-17-18------19-20-21-22-23-24-+
| O | | O O O X X |
| O | | O O O X |
| | | O O |
| | | |
| | | |
| |BAR| |
| | | |
| | | X |
| | | X X | +---+
| O | | X X X X | | 2 |
| O O O O | | X X X X X | +---+
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 114 O: 126 X-O: 0-0
Cube: 2, X own cube
X to play 66
---
Tim Chow

23/11* 22/10*
X's stronger board favors the double hit. Additionally, this play emasculates O's reception committee in the outfield.
--
BD

Paul

2016-09-15 11:21:36 UTC

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I don't see any reason not to play the double hit. For most problems, there are tradeoffs involving upsides and downsides but I don't see any downside to the double hit and the upsides are obvious.
Note the strong diversification: 5's and 1's cover, 2's and 3's hit on the 8 point. Perhaps this is more a cautionary tale than a problem, because the double hit would be easy to miss.
A problem where Walting is essential therefore, because hitting twice is obvious once you see it. (I didn't Walt unfortunately).

Paul

m***@gmail.com

2016-09-15 19:10:10 UTC

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Since we can't cover the ace point play the all weather move. Hit 2.

Tim Chow

2016-09-16 17:35:02 UTC

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XGID=-ACB-BD-a-aab-----bcbcBA--:1:1:1:66:0:0:0:0:10

X:Player 1 O:Player 2
Score is X:0 O:0. Unlimited Game
+13-14-15-16-17-18------19-20-21-22-23-24-+
| O | | O O O X X |
| O | | O O O X |
| | | O O |
| | | |
| | | |
| |BAR| |
| | | |
| | | X |
| | | X X | +---+
| O | | X X X X | | 2 |
| O O O O | | X X X X X | +---+
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 114 O: 126 X-O: 0-0
Cube: 2, X own cube
X to play 66

The double hit is definitely the right play against any opponent. Paul said
that he did not see any downside to the double hit; the only downside I see
is that it fails to leap all three checkers over O's prime. I had been
preoccupied up to this point with O's prime since I was in imminent danger
of crunching, so my instinct was to take the opportunity to solve the problem
of leaping O's prime once and for all. But 66 is a game changer and the
position must be assessed afresh. Leaping the four-prime is nowhere near as
productive as hitting a second checker, even if gammons didn't count (which
they do).

1. XG Roller++ 23/11* 22/10* eq:+0.989
Player: 70.41% (G:54.83% B:1.87%)
Opponent: 29.59% (G:8.23% B:0.64%)

2. XG Roller++ 23/11* 22/16(2) eq:+0.695 (-0.294)
Player: 63.17% (G:39.61% B:1.13%)
Opponent: 36.83% (G:9.30% B:0.42%)

eXtreme Gammon Version: 2.19.208.pre-release

---
Tim Chow