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is Neil Kazaross score: 1 pip: 46 | ||||||||||||||||

11 point match | ||||||||||||||||

pip: 89 score: 2 is USBGF Members | ||||||||||||||||

XGID=aCBBBBA-----A---A-----cfA-:1:1:1:00:2:1:0:11:10 | ||||||||||||||||

on roll, cube action? |

Analyzed in Rollout | No redouble | Redouble/Take |

Player Winning Chances: | 69.99% (G:0.00% B:0.00%) | 70.05% (G:0.00% B:0.00%) |

Opponent Winning Chances: | 30.01% (G:6.46% B:0.35%) | 29.95% (G:6.61% B:0.65%) |

Cubeless Equities | +0.326 | +0.662 |

Cubeful Equities | ||

No redouble: | +0.703 | ±0.006 (+0.697..+0.709) |

Redouble/Take: | +0.478 (-0.225) | ±0.007 (+0.471..+0.485) |

Redouble/Pass: | +1.000 (+0.297) | |

Best Cube action: No redouble / Take | ||

Percentage of wrong pass needed to make the double decision right: 30.1% | ||

Rollout details | ||

1296 Games rolled with Variance Reduction. Dice Seed: 73133427 Moves: 4-ply, cube decisions: XG Roller+ | ||

Double Decision confidence: | 100.0% | |

Take Decision confidence: | 100.0% | |

Duration: 4 minutes 10 seconds |

eXtreme Gammon Version: 2.10, MET: Kazaross XG2

`USBGF Members vote:`

[24] **No Redouble**

[19] Redouble

and Steve Sax (backgammonplayer@msn.com) teach at the Backgammon Learning Center, and can be contacted for lessons via email. |

**Grant Hoffman recommends: No Redouble**

We cover with 18 numbers (6’s + 55) so we miss with 18 numbers. On those 18 numbers or 50% of the time, we get hit 31% of the time, so that is 50% x 30% = 15% winning chances (slightly more as we have used 30% rather than 31% for easy of calculation). If we get hit, Neil could win a Gammon here. If he hits and is unlikely to win a gammon then we could be looking at an 8 cube.

Now suppose we do cover. With our spares in the best position (one each on the 4, 5 and 6 points), Neil will win 16.5% of the time with a gap on his 1 point (reference positions are useful). Therefore, he must win a greater % than that even if we cover due to our checker on our 1 point.

Put the above 2 scenarios together and I would not be doubling or Redoubling here.

**Steve Sax recommends: No Redouble**

One thing we never want to do is to double or re-double if we have no market losers. An exception for that would be if you got a very strong read that your opponent is going to pass.

Barring that in this position even if we gave us a 42 to cover and close the board, it would only be the barest of passes as it rolls out to 1.009.

That’s efficient enough for me.

However, how do we know it’s only a bare pass as this isn’t your typical “hit checker” reference position.

There is a baseline reference position that you need to know to assist you in knowing the correct cube action in these types of positions.

That position is having one checker on the bar, five checkers off, six on our ace and three on our deuce. Our opponent has a closed board with spares on the six, five and four point. That is a very strong redouble and a bare take for money.

However additional skills will be needed to interpolate this reference position into the position in question today. What we need to do is to think about the differences between the reference position and the position in question and how they impact you in a positive and negative way.

(1) The first major difference is the fact that our board isn’t closed yet. That’s the biggest factor even more than the score. Half of our numbers close the board but that means that half of them don’t.

So after we don’t cover (and they won’t lift), Neil will hit 11/36 times. So a little less than 1/6 times, Neil will be in and we will be on the bar with one or more checkers. Not a position we want to arrive at especially having given up the cube.

(2) The score of the match is another factor to consider. The fact that we lead in the match generally means we should be more conservative in giving up the cube and this case is no exception.

(3) We have a piece out of play on our one point. Even if we close the board and get our two spare checkers to the six and five points, the checker on the ace point might not be efficiently borne off which will give Neil extra chances to race around the board if we have to break a point sooner than we want to.

(4) What we do have in our favor is that Neil has a gap on his one point and nine checkers behind that gap. That is a huge disadvantage should we close the board, because we rate to get a couple of checkers off before having to open a point in our board (most often the six point).

Given that, even if Neil comes in on the first roll, we will be on roll and probably be off in seven rolls. If Neil comes in with let’s say 63, he will be off in seven rolls, so even if Neil comes in on the first roll he will be an underdog and if he doesn’t come in for one, two or three additional shakes his winning chances diminish rapidly.

This is partly because Neil’s board is weak, which means that we can bear off rather aggressively. In retrospect, we might break our board when bearing off by breaking the five or four point, taking a checker off and leaving a gap.

That might not seem like optimal bear off strategy, but it does help to contain Neil a bit longer and if Neil does come in, he will have borne off an additional checker making his winning chances even more slim.

Having gone through all this analysis, there are so many variables that it’s an unreasonable goal to be responsible to know all the possible reference positions.

You’ll simply have to weigh the pros and cons and make an educated guess what’s right to do.

That may not be a satisfactory answer but it gets us closer to the correct decision than had we no knowledge of the baseline reference position.

is Neil Kazaross score: 1 pip: 46 | ||||||||||||||||

11 point match | ||||||||||||||||

pip: 89 score: 2 is USBGF Members | ||||||||||||||||

XGID=aCBBBBA-----A---A-----cfA-:1:1:1:43:2:1:0:11:10 | ||||||||||||||||

to play 43 |

eXtreme Gammon Version: 2.10