Thanks, Mike. I looked at this position a little bit more, and came to a somewhat different conclusion. I think the point is that Blue's blot on the 18pt is just too vulnerable, and you have to move it out of harm's way. See for example the variant positions below.
Here, making the 3pt doesn't give White another escaping roll, but it's still a double whopper.
The score is: gnubg 9, tchow 11 (match to 13 points)
| gnubg | 121 |
|---|---|
| |
| tchow | 141 |
Position ID: cebOABCY2w4gAw Match ID: cAmvAZAAWAAA | |
• tchow moves 9/3 6/3
Alert: very bad move ( -0.194)
| # | Ply | Move | Equity | |
|---|---|---|---|---|
| 1 | 4 | 18/12 9/6 | +0.290 | |
| 0.617 0.152 0.003 - 0.383 0.059 0.001 | ||||
| 2 | 4 | 18/9 | +0.243 ( -0.047) | |
| 0.603 0.135 0.002 - 0.397 0.055 0.001 | ||||
| 3 | 4 | 18/15 9/3 | +0.191 ( -0.099) | |
| 0.601 0.161 0.004 - 0.399 0.082 0.002 | ||||
| 4 | 4 | 18/12 6/3 | +0.184 ( -0.106) | |
| 0.596 0.146 0.003 - 0.404 0.076 0.002 | ||||
| • | 5 | 4 | 9/3 6/3 | +0.096 ( -0.194) |
| 0.574 0.152 0.005 - 0.426 0.086 0.002 | ||||
Here, it's a whopper not to make the 3pt.
The score is: gnubg 9, tchow 11 (match to 13 points)
| gnubg | 121 |
|---|---|
| |
| tchow | 135 |
Position ID: cebOABCYtw0EAw Match ID: cAmvAZAAWAAA | |
• tchow moves 9/3 6/3
| # | Ply | Move | Equity | |
|---|---|---|---|---|
| • | 1 | 4 | 9/3 6/3 | +0.323 |
| 0.625 0.181 0.005 - 0.375 0.063 0.002 | ||||
| 2 | 4 | 15/9 6/3 | +0.203 ( -0.120) | |
| 0.594 0.154 0.004 - 0.406 0.066 0.002 | ||||
In the previous position, you might argue that the reason 15/9 6/3 is a whopper is that Blue's checker is already well-placed so you don't want to advance it. That's part of the story but I don't think it's the real explanation. The two positions below should help illustrate that the amount of outfield control exerted by Blue's checker, while important, isn't the overriding consideration.
The score is: gnubg 9, tchow 11 (match to 13 points)
| gnubg | 121 |
|---|---|
| |
| tchow | 138 |
Position ID: cebOABCYtw0gAw Match ID: cAmtAZAAWAAA | |
• tchow moves 18/13
| # | Ply | Move | Equity | |
|---|---|---|---|---|
| • | 1 | 4 | 18/13 | +0.321 |
| 0.627 0.154 0.003 - 0.373 0.059 0.001 | ||||
| 2 | 4 | 18/15 6/4 | +0.197 ( -0.124) | |
| 0.594 0.152 0.004 - 0.406 0.070 0.002 | ||||
The score is: gnubg 9, tchow 11 (match to 13 points)
| gnubg | 121 |
|---|---|
| |
| tchow | 135 |
Position ID: cebOABCYtw0EAw Match ID: cAmtAZAAWAAA | |
• tchow moves 15/12 6/4
Alert: doubtful move ( -0.038)
| # | Ply | Move | Equity | |
|---|---|---|---|---|
| 1 | 4 | 15/10 | +0.291 | |
| 0.618 0.154 0.003 - 0.382 0.058 0.001 | ||||
| • | 2 | 4 | 15/12 6/4 | +0.253 ( -0.038) |
| 0.603 0.156 0.003 - 0.397 0.060 0.001 | ||||
| 3 | 4 | 15/13 6/3 | +0.249 ( -0.041) | |
| 0.611 0.161 0.004 - 0.389 0.072 0.002 | ||||