Game 1, move 11 : Herd 3-3

[diane]

move?

[KDP]

Spoiler

18-15 (2) 8-5,7-4.  it brings two checkers into our home board, partially closes the gap on the 5 and gives us one more, albeit small chance to hit

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[Julia_H]

Spoiler

The simple question is, do we want one or two long backstops, or are we giving up the bar and running? Don't forget, our board which is bottom-heavy is rather worse than a straight pipcount suggests, while Linus's is pretty good.

On 17 White rolls (any 8 or greater) it's all a wash anyway.
On 13 rolls, (any 6 or smaller) if we've stayed back at all, White just plays inside and we get a shot at a 7 to hit. 1/3 of the time he comes straight back on, the rest of the time we cube as we'll have our firepower in a better place next roll.
On 4 rolls (52, 43), if we keep a single backstop it's game over. With two backstops, White again plays inside, with none White runs.
On 2 rolls (61), White leaves us a single direct shot if we've kept the bar point, kills us if we have a blot there, runs if neither.

So, on this roll staying back turns 4% of marginally-behind races into extra wins, maybe another 1% if he can't get past us next time. Staying back with one man additionally turns 18% of marginally-behind races into losses. Does dumping two men deep into our board cost us 4% in the races by wasting pips? I can't do that in my head but intuitively I think it does - wasting 6 pips is almost a complete roll lost. So I'm with KDP - take two crossovers 8/5 7/4, then shunt the back men along. The extra vig from a White 11/22/12/13 is a nice little bonus.

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[ah_clem]

Spoiler

We'll be about 5 pips behind in the race after this play, and a bit worse in EPC due to the spare on the ace and the gap on the 5.  A racing win is still a  possibility, but only in the range of ~30%. So, I think our strongest chance is to maximize contact rather than giving him an easy way to run past us.  Which is to say that 18/15(2) or 18/12(2) may be best for racing chances, i don't think we want to put our eggs in that basket.

I'd look seriously at 18/9 8/5 - we don't need both checkers to hit him, but that gives him another 6 rolls to run past us, so i don' think that's the right idea.

I'm going to go with 8/2 7/1 - yes it is awful in the way it wastes pips and leaves the gap on the 5, but I think we need to maintain the 18 point and if we play from the 6 our hit is much less strong, assuming we get one.

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[ah_clem]

XGR++

Spoiler

I found this move confusing, but apparently the herd didn't.  18/15(2) 8/5 7/4 is best by a good margin.


XGID=-CBBB-BAA--a------Bdbbcc--:0:0:1:33:0:0:0:5:10

X:Player 1   O:Player 2
Score is X:0 O:0 5 pt.(s) match.
+13-14-15-16-17-18------19-20-21-22-23-24-+
|                X |   | O  O  O  O  O    |
|                X |   | O  O  O  O  O    |
|                  |   | O        O  O    |
|                  |   | O                |
|                  |   |                  |
|                  |BAR|                  |
|                  |   |                  |
|                  |   |                  |
|                  |   |                X |
|                  |   | X     X  X  X  X |
|    O        X  X |   | X     X  X  X  X |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count  X: 84  O: 71 X-O: 0-0/5
Cube: 1
X to play 33

    1. XG Roller++ 18/15(2) 8/5 7/4             eq:-0.511
      Player:   32.49% (G:0.07% B:0.00%)
      Opponent: 67.51% (G:0.41% B:0.01%)

    2. XG Roller++ 18/15(2) 8/2                 eq:-0.600 (-0.089)
      Player:   29.23% (G:0.05% B:0.00%)
      Opponent: 70.77% (G:0.10% B:0.00%)

    3. XG Roller++ 18/15(2) 8/5 6/3             eq:-0.603 (-0.092)
      Player:   29.26% (G:0.05% B:0.00%)
      Opponent: 70.74% (G:0.87% B:0.04%)

    4. XG Roller++ 18/9 8/5                     eq:-0.632 (-0.122)
      Player:   29.16% (G:0.21% B:0.00%)
      Opponent: 70.84% (G:1.84% B:0.07%)

    5. XG Roller++ 18/12(2)                     eq:-0.645 (-0.134)
      Player:   27.75% (G:0.01% B:0.00%)
      Opponent: 72.25% (G:0.01% B:0.00%)

    6. XG Roller++ 8/2 7/1                      eq:-0.691 (-0.180)
      Player:   26.63% (G:0.15% B:0.00%)
      Opponent: 73.37% (G:0.85% B:0.02%)


eXtreme Gammon Version: 2.10, MET: Kazaross XG2

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