Primer for priming, anyone?

[Robert Zimmerman]

I'm trying to understand when to step up to the edge of a prime with a single back checker vs. staying back. Positions such as:

XGID=--BbB-CBB----C--a-ccbbb-A-:1:1:1:21:1:0:0:7:10

Score is X:1 O:0 7 pt.(s) match.
+13-14-15-16-17-18------19-20-21-22-23-24-+
| X O O | | O O O O X |
| X O | | O O O O |
| X O | | O |
| | | |
| | | |
| |BAR| |
| | | |
| | | |
| | | X | +---+
| X X | | X X O X | | 2 |
| X X | | X X O X | +---+
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 123 O: 116 X-O: 1-0/7
Cube: 2, X own cube
X to play 21

Any good resources out there that might shed some light and lighten my load?

Bob

[Robert Zimmerman]

Versus this:

XGID=---bB-DBC----Ca-abbcbb--A-:0:0:1:42:1:0:0:7:10

Score is X:1 O:0 7 pt.(s) match.
+13-14-15-16-17-18------19-20-21-22-23-24-+

| X O O O O | | O O O X |

| X O O | | O O O |
| X | | O |
| | | |
| | | |

| |BAR| |
| | | |
| | | X |
| X | | X |

| X X | | X X O |

| X X | | X X O |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 133 O: 130 X-O: 1-0/7
Cube: 1
X to play 42

[Stick Rice]

On Thursday, March 23, 2023 at 10:50:42 AM UTC-4, Robert Zimmerman wrote:

As an aside, when you're trying to understand a concept/comparing positions, you should make it unlimited play so there's no potential for outside noise due to the score.

Stick

[Robert Zimmerman]

Thanks. Noted.

[Timothy Chow]

One of the first things I look at is the pip count. If I'm behind
then I'm less inclined to step up. What am I trying to do, convert
to a losing race?

The next thing I look at is the opponent's attacking potential. Here,
the opponent has a better board and an anchor, so is happy to attack.
That also makes me not want to step up.

Of course, in any position, there's always the question, what else are
you going to play? If a move looks bad but everything else looks worse,
then one is going to choose the least evil option. My inclination is
to make the 5pt here. It does leave a direct shot but it gives us the
best upside if we're missed.

---
Tim Chow

[Timothy Chow]

On 3/23/2023 10:56 AM, Robert Zimmerman wrote:
> XGID=---bB-DBC----Ca-abbcbb--A-:0:0:1:42:1:0:0:7:10
>
> Score is X:1 O:0 7 pt.(s) match.
> +13-14-15-16-17-18------19-20-21-22-23-24-+
> | X O O O O | | O O O X |
> | X O O | | O O O |
> | X | | O |
> | | | |
> | | | |
> | |BAR| |
> | | | |
> | | | X |
> | X | | X |
> | X X | | X X O |
> | X X | | X X O |
> +12-11-10--9--8--7-------6--5--4--3--2--1-+
> Pip count X: 133 O: 130 X-O: 1-0/7
> Cube: 1
> X to play 42

Here the race is about even, but otherwise I'd analyze it similarly.
In fact, here the alternative play 13/7 doesn't have the liability
of leaving a direct shot, so I'm even less inclined to step up than
in the other problem.

---
Tim Chow

[Robert Zimmerman]

Those are helpful comments, Tim. Once again, I'm overcomplicating the game. I had ideas about avoiding being put up on the bar so that you could advance your checkers to avoid being gammoned. But after trying different positions, I can't really say there's any truth to that idea except perhaps for rare cases. Other faulty notions littered my mind. Thanks for helping clean out the clutter.
Bob