Position # 12

[PersianLord]

Red is leading 2-0 in a 9 pointer match and is also ahead in pip-counts (120 to 144). What's the right move with a 4-2 roll?





If you feel that my problems are too easy to slove, plz let me know. May be I'm the most novice here and these positions may appeal just to me 

[spielberg]

Spoiler

Red's problem here is the very imminent collapse of his 6 prime. White's timing to retain Red's loose man on the 23 also seems poorish. Accordingly I hit loose with a slot to my 2 point - even if I'm hit back I don't care that much. The 2 then plays itself as 13-11 would then be VERY obvious. This move is also very likely to give me a good cube on my next roll - lots of the time I will be too good to cube yet would against many (hoping they'd take obv.)

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I found this an interesting one to have a think about PersianLord - and of course your problems aren't "too easy". Even if they were they'd encourage debate and not least give a glimpse of how the likes of hardy/dorb's etc thought processes work. Usually, in fact almost always, an expert's explanation of why a move is correct is extremely useful.

[sixty_something]

yes, PersianLord, your contributions are most welcomed .. the point of this series is to enable all users beginner and advanced to share problems, solutions, and discussion over approaches toward the goal of all of us improving our skills

when i first tried posting a problem we had a lengthy discussion on what form or style to use .. you may be interested in reading Re: posting a position as a problem was a problem  .. basically, we've agreed to welcome any style and any problems

the one thing you might consider adding is a solution using GNUbg or Snowie analysis or your own explanation, if different or helpful .. i developed the habit of attaching my answers in a simple text file, but putting it behind a spoiler tag would be just as effective .. i also attach with the PNG of the board image in case the link to the on-line file is ever disabled .. finally, i include the Position ID/Match ID for convenience of anyone interested in inputting the problem into GNUbg or Snowie

for naming, i selected a Cube 1xx and Move 1xx convention simply to enable new and regular readers to jump in at a starting point or where they last participated .. but any and all styles are welcomed

so thanks, PersianLord, for your contributions .. i look forward to seeing more 



Doubt yourself and you doubt everything you see. Judge yourself and you see judges everywhere. But if you listen to the sound of your own voice, you can rise above doubt and judgment. And you can see forever.
-- Nancy Kerrigan (1969- ) two-time American Olympic figure skating medalist and 1993 U.S. champion.

[PersianLord]

yes, PersianLord, your contributions are most welcomed .. the point of this series is to enable all users beginner and advanced to share problems, solutions, and discussion over approaches toward the goal of all of us improving our skills

when i first tried posting a problem we had a lengthy discussion on what form or style to use .. you may be interested in reading Re: posting a position as a problem was a problem  .. basically, we've agreed to welcome any style and any problems

the one thing you might consider adding is a solution using GNUbg or Snowie analysis or your own explanation, if different or helpful .. i developed the habit of attaching my answers in a simple text file, but putting it behind a spoiler tag would be just as effective .. i also attach with the PNG of the board image in case the link to the on-line file is ever disabled .. finally, i include the Position ID/Match ID for convenience of anyone interested in inputting the problem into GNUbg or Snowie

for naming, i selected a Cube 1xx and Move 1xx convention simply to enable new and regular readers to jump in at a starting point or where they last participated .. but any and all styles are welcomed

so thanks, PersianLord, for your contributions .. i look forward to seeing more 



Doubt yourself and you doubt everything you see. Judge yourself and you see judges everywhere. But if you listen to the sound of your own voice, you can rise above doubt and judgment. And you can see forever.
-- Nancy Kerrigan (1969- ) two-time American Olympic figure skating medalist and 1993 U.S. champion.

Many thanks for the encouraging and warm message, my friend . I will definitly be more committed in my posts from now on.

About the solution, I had intended to include it in the post and via the spoiler botton, but I thought that it would be better to let the members make their decision and vote and after 1 day to post the GNUBG's answer that can be found in my blog. Now as you say, I will include the solution in the 1st posts.

Again thanks for the nice imput man.

[PersianLord]

OK chaps. Here is the analysis, verified by GNUBG which can be found in my blog.

Spoiler

As red has bulid a full prime in front of 3 white checkers, he must pay attention to the "timing" factor, as white also has a potential to contain the red's back runner. So the game may turn into a mutual priming battle in which the player who has better timing will win. Here is GNUBG's solution :

    1. Cubeful 2-ply    13/11 6/2*                   MWC:  68.62%
       0.765 0.267 0.013 - 0.235 0.046 0.001
   
    2. Cubeful 2-ply    13/7                            MWC:  67.78% ( -0.83%)
       0.747 0.236 0.010 - 0.253 0.042 0.001
     
    3. Cubeful 2-ply    13/9 6/4                       MWC:  66.92% ( -1.69%)
       0.723 0.231 0.010 - 0.277 0.051 0.001
       
    4. Cubeful 2-ply    9/7 9/5                         MWC:  64.60% ( -4.02%)
       0.656 0.241 0.013 - 0.344 0.086 0.002
     
    5. Cubeful 2-ply    9/7 6/2*                       MWC:  63.71% ( -4.91%)
       0.642 0.256 0.014 - 0.358 0.124 0.006

Hitting loose is the best move, as it improves red's timing. If white hit the blot on the 2-point from the bar, an ideal position will occur for red, as white will be forced to crush his prime without escaping his back men who are trapped behind red's 6-point prime. Thus, red can dance merrily a while and then will be faced with a weak white home board and can risk more to hit all the blots he can and go for an easy victory with nice gammon potentials.

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