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  • Re: Surprised by XG

    From Timothy Chow@21:1/5 to All on Tue Dec 12 23:27:44 2023
    For what it's worth, below is an XGR+ rollout of the position. Murat's
    play is on top, albeit by a very narrow margin. Note that the numbers
    are displayed to 4 decimal places instead of the usual 3 decimal places.

    XGID=-BBB-CCa-----B----bbbbbbbA:1:-1:-1:11:2:8:0:11:10

    Score is X:8 O:2 11 pt.(s) match.
    +13-14-15-16-17-18------19-20-21-22-23-24-+
    | X | | O O O O O |
    | | | O O O O O |
    | | | O O |
    | | | |
    | | | |
    | |BAR| |
    | | O | |
    | | | |
    | | | | +---+
    | O X | | X X X X X X | | 2 |
    | O X | | X X X X X X | +---+
    +12-11-10--9--8--7-------6--5--4--3--2--1-+
    Pip count X: 74 O: 96 X-O: 8-2/11
    Cube: 2, X own cube
    X to play 11

    1. Rollout¹ 7/5(2) eq:+1.0841
    Player: 97.30% (G:21.85% B:0.21%)
    Opponent: 2.70% (G:0.02% B:0.00%)
    Confidence: ±0.0010 (+1.0831..+1.0851) - [77.9%]

    2. Rollout¹ 18/15 7/6 eq:+1.0835 (-0.0006)
    Player: 97.10% (G:22.33% B:0.21%)
    Opponent: 2.90% (G:0.01% B:0.00%)
    Confidence: ±0.0011 (+1.0824..+1.0845) - [18.6%]

    3. Rollout¹ 18/14 eq:+1.0829 (-0.0011)
    Player: 97.35% (G:21.62% B:0.22%)
    Opponent: 2.65% (G:0.00% B:0.00%)
    Confidence: ±0.0010 (+1.0820..+1.0839) - [3.3%]

    4. Rollout¹ 7/6 7/4 eq:+1.0823 (-0.0018)
    Player: 97.11% (G:22.16% B:0.21%)
    Opponent: 2.89% (G:0.02% B:0.00%)
    Confidence: ±0.0010 (+1.0812..+1.0833) - [0.2%]

    ¹ 2592 Games rolled with Variance Reduction.
    Dice Seed: 271828
    Moves and cube decisions: XG Roller+
    Search interval: Gigantic

    eXtreme Gammon Version: 2.19.211.pre-release, MET: Kazaross XG2

    ---
    Tim Chow

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  • From Timothy Chow@21:1/5 to All on Wed Dec 13 09:13:37 2023
    On 12/13/2023 2:55 AM, MK wrote:

    Granted they are all very close but shouldn't we
    expect a little more consistency?

    No. Why would anyone expect that when the plays are so close?

    ---
    Tim Chow

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  • From Timothy Chow@21:1/5 to All on Sat Dec 23 08:34:29 2023
    On 12/22/2023 10:48 AM, MK wrote:

    Contrary to your comments in the other thread,
    they do indeed get more consistent with rollouts
    but again with unexpected exceptions. Let's look:

    There is nothing unexpected about your results. You have
    omitted the most important quantity from your rollout results,
    which is the confidence interval. It is to be expected that
    there will be random fluctuations within, say, two times the
    width of the confidence interval.

    ---
    Tim Chow

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