Coming home against a 32 backgame, 51 to play

Discussion:

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BlueDice

2017-04-17 12:00:41 UTC

XGID=-abc-DEC---B-A---bacab----:1:-1:1:51:0:0:0:0:10

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-+
| X O O | | O O O | +---+
| O | | O O | | 2 |
| | | O | +---+
| | | |
| | | |
| |BAR| |
| | | X |
| | | X X |
| X | | X X O |
| X X | | X X O O |
| X X | | X X O O O |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 106 O: 190 X-O: 0-0
Cube: 2, O own cube
X to play 51
--
BD

Tim Chow

2017-04-17 23:45:49 UTC

Permalink

Post by BlueDice
XGID=-abc-DEC---B-A---bacab----:1:-1:1:51:0:0:0:0:10
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-+
| X O O | | O O O | +---+
| O | | O O | | 2 |
| | | O | +---+
| | | |
| | | |
| |BAR| |
| | | X |
| | | X X |
| X | | X X O |
| X X | | X X O O |
| X X | | X X O O O |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 106 O: 190 X-O: 0-0
Cube: 2, O own cube
X to play 51

Safe play looks bad here; it gives O a phantom 1-2-3-4 backgame with good
timing. O's offensive structure is still relatively weak so I would try
to improve my own structure with 6/1* 5/4. Slotting the 4pt is a prelude
to making it, and then 6/1* is the only reasonable 5. Things could go
badly, of course, but even if we're hit back, we are probably not in that
much danger.

---
Tim Chow

Michael

2017-04-18 10:56:58 UTC

Permalink

This is the sort of backgame that looks it's going to be successful for O. Imo X has to recirculate a checker or some checkers , or try to block O.
13/8 6/5 serves both.

Walt

2017-04-19 20:48:52 UTC

Permalink

Mobility and pure play are the watchwords for success in back games.

13/7 looks obvious, but unless X fills in the four point he'll have
trouble later, so I'll slot that now. I'd also like to make the ace
point, so might as well slot that now too. I can't say I'll be upset if
I'm hit, what I really don't want is for O to make the four point.

5/1* 5/4

--
//Walt

BlueDice

2017-04-22 16:38:42 UTC

Permalink

I rolled out two plays to contrast safe vs bold. The others are XGR++.
The bold play 6/1* 5/4 comes out on top

1. Rollout¹ 6/1* 5/4 eq:+0.006
Player: 51.09% (G:27.58% B:2.04%)
Opponent: 48.91% (G:9.67% B:0.47%)
Confidence: ±0.016 (-0.009..+0.022) - [100.0%]
Duration: 14 minutes 47 seconds

2. Rollout¹ 13/7 eq:-0.070 (-0.076)
Player: 48.15% (G:26.05% B:1.72%)
Opponent: 51.85% (G:7.94% B:0.32%)
Confidence: ±0.013 (-0.083..-0.057) - [0.0%]
Duration: 12 minutes 58 seconds

3. XG Roller++ 11/10 11/6 eq:-0.005 (-0.011)
Player: 49.32% (G:27.65% B:2.23%)
Opponent: 50.68% (G:7.58% B:0.29%)

4. XG Roller++ 13/8 6/5 eq:-0.019 (-0.025)
Player: 49.45% (G:26.75% B:2.19%)
Opponent: 50.55% (G:8.56% B:0.33%)

5. XG Roller++ 11/5 eq:-0.020 (-0.026)
Player: 48.92% (G:27.29% B:2.31%)
Opponent: 51.08% (G:7.87% B:0.32%)

6. XG Roller++ 11/10 6/1* eq:-0.030 (-0.036)
Player: 49.09% (G:27.59% B:2.16%)
Opponent: 50.91% (G:9.21% B:0.48%)

7. XG Roller++ 13/12 11/6 eq:-0.033 (-0.039)
Player: 48.59% (G:26.61% B:2.04%)
Opponent: 51.41% (G:7.54% B:0.27%)

8. XG Roller++ 13/12 6/1* eq:-0.042 (-0.048)
Player: 48.43% (G:27.24% B:2.00%)
Opponent: 51.57% (G:8.49% B:0.35%)

9. XG Roller++ 13/8 7/6 eq:-0.045 (-0.051)
Player: 48.74% (G:26.04% B:2.16%)
Opponent: 51.26% (G:8.66% B:0.34%)

10. XG Roller++ 7/1* eq:-0.058 (-0.064)
Player: 47.91% (G:26.88% B:2.05%)
Opponent: 52.09% (G:8.57% B:0.35%)

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

eXtreme Gammon Version: 2.10

--
BD