Priming battle

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Timothy Chow

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May 17, 2022, 7:01:49 AMMay 17
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XGID=-aBBB-BBA--B---b-bbdcB-a--:0:0:1:51:0:0:0:0:10

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-+
| O O O | | O O X O |
| O O O | | O O X |
| | | O O |
| | | O |
| | | |
| |BAR| |
| | | |
| | | |
| | | |
| X X | | X X X X |
| X X X | | X X X X O |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 116 O: 115 X-O: 0-0
Cube: 1
X to play 51

---
Tim Chow

Timothy Chow

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May 20, 2022, 8:20:02 AMMay 20
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X is in big trouble if O rolls a 4 regardless, and slotting gives
X the biggest upside if O does not roll a 4. Nevertheless, I was
surprised at how big an error XG thought my play of 11/10 11/6 was.

1. Rollout¹ 11/5 eq:+0.527
Player: 65.18% (G:12.78% B:0.33%)
Opponent: 34.82% (G:7.23% B:0.24%)
Confidence: ±0.008 (+0.519..+0.535) - [100.0%]

2. Rollout¹ 11/6 8/7 eq:+0.257 (-0.270)
Player: 57.96% (G:10.80% B:0.29%)
Opponent: 42.04% (G:6.61% B:0.24%)
Confidence: ±0.011 (+0.246..+0.268) - [0.0%]

3. Rollout¹ 11/10 11/6 eq:+0.193 (-0.334)
Player: 56.39% (G:10.13% B:0.24%)
Opponent: 43.61% (G:6.00% B:0.20%)
Confidence: ±0.010 (+0.183..+0.203) - [0.0%]

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

eXtreme Gammon Version: 2.19.207.pre-release

---
Tim Chow

Stick Rice

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May 20, 2022, 2:56:28 PMMay 20
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With your play when the opponent doesn't roll a four you make your five point and a six prime cleanly about 1/4th of the time. So out of the 25 games the opponent doesn't roll a four you are making your five point about 6 games.

By slotting in the games the opponent doesn't roll a four you make your five point and a six prime cleanly about 3/4th of the time. So out of the 25 games the opponent doesn't roll a four you are making your five point about 19 games. This play also leaves you a good six to play which with the other play is otherwise awful, and doesn't duplicate your own fives. So it's no surprise the huge disparity between the plays.

Stick

Timothy Chow

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May 21, 2022, 11:05:00 AMMay 21
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On 5/20/2022 2:56 PM, Stick Rice wrote:
> By slotting in the games the opponent doesn't roll a four you make your five point and a six prime cleanly about 3/4th of the time. So out of the 25 games the opponent doesn't roll a four you are making your five point about 19 games. This play also leaves you a good six to play which with the other play is otherwise awful, and doesn't duplicate your own fives. So it's no surprise the huge disparity between the plays.

I wouldn't have been surprised by a .2 disparity, but .3+ surprises me.

---
Tim Chow

atila...@gmail.com

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May 21, 2022, 6:04:38 PMMay 21
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21 Mayıs 2022 Cumartesi tarihinde saat 18:05:00 UTC+3 itibarıyla Tim Chow şunları yazdı:
The right play and theme is 11/5. And Stick Rice’s comment about this move is quite satisfying. But failure to grasp the main theme is not the only reason why the error is so great. I think there are 3 more important points.

The fist is O’s blot on the 23 point. The checker duplicates O’s fours. In variant 1, I moved that checker from 23 to 22. And I removed it in variant 2.

Variant 1

XGID=-aBBB-BBA--B---b-bbdcBa---:0:0:1:51:0:0:3:0:10

1. Rollout¹ 11/5 eq:+0,470
Player: 62,77% (G:12,67% B:0,31%)
Opponent: 37,23% (G:7,67% B:0,29%)
Confidence: ±0,008 (+0,462..+0,478) - [100,0%]

2. Rollout¹ 11/6 8/7 eq:+0,271 (-0,199)
Player: 57,30% (G:11,07% B:0,32%)
Opponent: 42,70% (G:6,32% B:0,25%)
Confidence: ±0,012 (+0,258..+0,283) - [0,0%]

3. Rollout¹ 11/10 11/6 eq:+0,216 (-0,254)
Player: 56,14% (G:10,82% B:0,30%)
Opponent: 43,86% (G:6,37% B:0,24%)
Confidence: ±0,012 (+0,204..+0,227) - [0,0%]

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

Variant 2

XGID=-aBBB-BBA--B---b-bbddB----:0:0:1:51:0:0:3:0:10

1. Rollout¹ 11/5 eq:+0,462
Player: 62,87% (G:13,19% B:0,32%)
Opponent: 37,13% (G:6,83% B:0,20%)
Confidence: ±0,008 (+0,453..+0,470) - [100,0%]

2. Rollout¹ 11/6 8/7 eq:+0,308 (-0,154)
Player: 58,48% (G:11,40% B:0,31%)
Opponent: 41,52% (G:6,12% B:0,23%)
Confidence: ±0,013 (+0,295..+0,320) - [0,0%]

3. Rollout¹ 11/10 11/6 eq:+0,224 (-0,237)
Player: 56,40% (G:11,00% B:0,28%)
Opponent: 43,60% (G:6,02% B:0,22%)
Confidence: ±0,012 (+0,212..+0,237) - [0,0%]

Second, John's timing is shaky. The third is the location of the cube. In the third variant, I made all the changes simultaneously. In other words, the cube is now at 2, no blots, and O has 2 checkers on the mid-point to play comfortably.

Variant 3

XGID=-aBBB-BBA--Bb--b-bbccB----:1:-1:1:51:0:0:3:0:10

X:Player 1 O:Player 2
Score is X:0 O:0. Unlimited Game, Jacoby Beaver

Pip count X: 116 O: 133 X-O: 0-0
Cube: 2, O own cube
X to play 51

1. Rollout¹ 11/5 eq:-0,138
Player: 50,27% (G:15,21% B:0,35%)
Opponent: 49,73% (G:8,90% B:0,38%)
Confidence: ±0,010 (-0,148..-0,128) - [100,0%]

2. Rollout¹ 11/6 8/7 eq:-0,199 (-0,062)
Player: 48,59% (G:14,13% B:0,29%)
Opponent: 51,41% (G:8,30% B:0,37%)
Confidence: ±0,011 (-0,210..-0,189) - [0,0%]

3. Rollout¹ 11/10 11/6 eq:-0,237 (-0,100)
Player: 47,09% (G:13,04% B:0,20%)
Opponent: 52,91% (G:7,63% B:0,34%)
Confidence: ±0,010 (-0,247..-0,227) - [0,0%]

Timothy Chow

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May 23, 2022, 8:36:36 AMMay 23
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On 5/21/2022 6:04 PM, atila...@gmail.com wrote:
> Second, John's timing is shaky.

Nice variants. But which player are you calling John?

---
Tim Chow

atila...@gmail.com

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May 23, 2022, 8:53:28 AMMay 23
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23 Mayıs 2022 Pazartesi tarihinde saat 15:36:36 UTC+3 itibarıyla Tim Chow şunları yazdı:
I don't know John :)) He is O
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