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Game 5 Move 12 the Herd to play 6-1

Started by ah_clem, December 07, 2010, 11:49:52 PM

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ah_clem


ah_clem

Spoiler

This is a juicy one.  Zorba has double-dog dared us to hit the blot on his midpoint.  Much as I'm tempted to hit him there just to do it, I don't think that it's the best play.

His straggler is the the thorn in our side, so I'd like to make that go away.  By pointing on it's bald little head it's outta there, and can't come back to bother us again.  If it enters it will enter on the 5 where it's too far froward to give us the fits it's giving us on the ace point.

Yes, this gives him a one in 18 fly shot from the bar to win while hitting on the 12 is completely "safe".  The thing is, if he anchors we have a persistent problem going forward, and he may have several chances to anchor.  I like the 1/18 chance myself.  The 17 times it works we're basically home free.



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stog


stiefnu

Spoiler
Quote13/12*, 12/6?
Yes, I think this looks ok, a hit with no possible return, that puts a builder on our 6-point.  Even if he makes the ace point, I can see him crunching or leaving us a shot before long.  And 13/7, 13/12* has its attractions too.  Then again ah-clem makes a strong argument...  Blimey, I don't know!  But I reckon I'll go for 13/12*, 12/6
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PersianLord

Spoiler
7/1*-2/1

No fancy moves here as we're inches away from getting rid of Zorba. I don't like giving him a possible ace-pt game by hitting.

PL
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The leftist's feelings of inferiority run so deep that he cannot tolerate any classification of some things as successful or superior and other things as failed or inferior. This also underlies the rejection by many leftists of the concept of mental illness and of the utility of IQ tests.  - T.K

diane

Spoiler
I like 13/12*/6...I like the ultra safe hit...the risk of him entering on the ace doesn't seem a big deal to me..we have some timing here.  If he does come in right away, we can keep moving while he either breaks a point or crunches at home. 

My main question is...I see 3 posts advocating the same move...but only one vote...mine.  What happened to the others?
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Never give up on the things that make you smile

ah_clem

#6
Spoiler

Quote from: PersianLord on December 08, 2010, 01:36:08 AM
7/1*-2/1

No fancy moves here as we're inches away from getting rid of Zorba. I don't like giving him a possible ace-pt game by hitting.


Interesting.  I would characterize 7/1* 2/1 as the "fancy" move and 13/12*/6 as the boring safe move.  I suppose the choice here is basically which scares you more: a 1/18 fly shot from the bar or the possibility of facing a poorly timed 1-5 backgame that will most likely turn into an ace-point game.

If we hit on the 12-point  I estimate he anchors ~50% of the time (11/36 to enter right away, and then diminishing possibilities with subsequent rolls).  An ace point game wins about 20%, so hitting on the 12 seems to give him about 10% GWC.

If we hit on the ace point he has an immediate 1/18 (5.6%) chance to whack us and we lose almost all of those.  Call it 5% with an immediate hit.  If he whiffs, our work is not done, but we'll probably win about 95% of the time after a whiff.  Since he misses about 95% of the time and wins about 5% of those we're at slightly less than 5% , so my back of the envelope calculation is that he's slightly less than 10% GWC with the ace point hit.

Thus the ace point hit seems to win more games, but not by much.  It probably wins more gammons, but those don't count.  OTOH, if we get gammoned, we lose the match. Hitting on the 12 won't lose very many gammons,  hitting on the ace doesn't lose many gammons either, but it certainly loses a lot more than the other play.  Taking the match score into consideration favors the safer hit on the 12.

I'm still not sure.  I'm going to stick with my play, mainly because I've lost way too many matches by playing overly conservatively when ahead in the match. I'm certainly OK with the hit on the 12.



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ah_clem

rollout

Spoiler

gnubg 0-ply likes the Herd's move.  The alternate hitting play on the 12 is pretty close, but it's obvious why the Herd's choice is better.

The ace point hit is not too far behind but clearly an error.  It wins almost as often, but it loses gammons at three times the rate.  At gammon-save, that's a problem. 



    1. Rollout          13/12*/6                     Eq.:  +0.643
       0.829 0.495 0.047 - 0.171 0.008 0.000 CL  +0.643 CF  +0.643
      [0.002 0.009 0.004 - 0.002 0.001 0.000 CL   0.004 CF   0.004]

    2. Rollout          13/12* 13/7                  Eq.:  +0.629 ( -0.013)
       0.823 0.474 0.044 - 0.177 0.008 0.000 CL  +0.629 CF  +0.629
      [0.002 0.009 0.004 - 0.002 0.001 0.000 CL   0.004 CF   0.004]

    3. Rollout          7/1* 2/1                     Eq.:  +0.606 ( -0.037)
       0.826 0.437 0.007 - 0.174 0.023 0.001 CL  +0.606 CF  +0.606
      [0.001 0.008 0.001 - 0.001 0.001 0.000 CL   0.003 CF   0.003]
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