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Difficult 5-3 on gridgammon 3 point match Difficult 5-3 on gridgammon 3 point match

08-04-2014 , 04:57 PM
Hi all,

Please note that's a 3 POINT MATCH on gridgammon.

After a bad start on 0-0 I had this position:

White - Pips 143. Match Score 0/3

Black - Pips 182. Match Score 0/3
Black to Play 5-3
Created with www.BGdiagram.com

XGID=a----AD-C---bC-bbc-e-A-C--:0:0:1:53:0:0:0:3:10

There are imo many candidate moves, what's your move and why as usual.
Thanks.
Difficult 5-3 on gridgammon 3 point match Quote
08-04-2014 , 07:52 PM
23/18, 8/5.

I actually don't see any other candidates. What else is there? You don't want to play a backgame unless you have to. It's way to early to try and make a second anchor.

Try to get your guys in play. 3 men on the 2 point is awful. Pop him out to maintain timing, control of the board, prevent yourself from getting army split.

Besides, he won't be happy to hit you on the bar point unless he enters with doubles. And even then at least the doubles won't make an inside point. Remember contact favors you down in the race and with better board.

What is your handle?
Difficult 5-3 on gridgammon 3 point match Quote
08-05-2014 , 06:58 AM
I am not sure whether the best bot choice is trivial. In spite of the bad equity I think that making the 18 point is not a bad move for a skilled player. White has no board, and a lot can happen. Maybe I would try for a good backgame if I have been faring well up until now. I made this a point of discussion in another thread.
Difficult 5-3 on gridgammon 3 point match Quote
08-05-2014 , 07:44 AM
OTB, I would probably have played 13/5, or even 23/18 21/18, but I really like 911's play.

P.S. There should be a book "Yogi and the backgames".
Difficult 5-3 on gridgammon 3 point match Quote
08-05-2014 , 09:07 AM
23/18 8/5 would be my play, and I'd be surprised if it was close.
Difficult 5-3 on gridgammon 3 point match Quote
08-05-2014 , 11:27 AM
Hi everyone, first post.

I don't really see the "many candidate moves". The 3 is obvious (8/5) and there are only two reasonable uses for the 5, 23/18 or 13/8. Although, it is not obvious to me why 23/18 is so much better, as other responders suggest.

Making the 18 point and leaving the blot on my 5 point feels so wrong that I don't consider it a candidate.
Difficult 5-3 on gridgammon 3 point match Quote
08-05-2014 , 12:56 PM
Quote:
Originally Posted by peachpie
Making the 18 point and leaving the blot on my 5 point feels so wrong that I don't consider it a candidate.
It feels wrong because you have learned about the golden five point. However, black is not in a hurry to build his homeboard, as there are four of his checkers in the other homeboard. Besides, it is not sure that white will hit. And at least, white will not be able to make the important 18 point himself.
Difficult 5-3 on gridgammon 3 point match Quote
08-05-2014 , 02:26 PM
I am truly surprised that anyone call this position as a simple one with no candidate moves.

I sincerely found three candidates:

1) 8/5 23/18

2) 13/5

3) 23/18 21/18

Instantly I discarded 13/5 since it is clearly hopeless: while it extabilish the 5 point it strippes the midpoint, and the little white prime blocks my 6 and if I roll that the next move i have to crash my position cuttig it into two disconnected part so 13/5 is a blunder confirmed by the rollout.

So I thought that was close between 1 and 3.

In favour of 23/18 21/18: this creates an outpost on white's bar point and a nice bridge for the 23 men, and it makes hard for my opponent to close me behind a prime making an annoying anchor for my oppo. It keeps my checkers connected and (for inside job911) the last thing on my mind was thinking to play a backgame. That move was made to try to pass into an high anchor game.

Obviously the drawback is that my 5 point remains uncovered, but what? having many men back one more doesn't change anything, having an anchor I think it's not even a threat.

In favour of 23/18 8/5: it makes the 5 point and with the 23/18 I think it's an action game play done with the better board but what? We just have a 2 point board and our oppo has only 1 man back. What's the point?

But reading the answers I'm glad that Bill's move it's obvious for anyone, because then it's simpler for me to get an explanation of that. I need it, but nobody gave it to me. Can somebody with great heart explain?

Many thanks.

For the record the better move is 23/18 8/5, yes it's not close (-0.155 the anchor play) but it's not a -0.3 blunder.
Difficult 5-3 on gridgammon 3 point match Quote
08-05-2014 , 02:41 PM
Interesting - sounds like the anchor play is actually better than 13/5. Can you post the equity for all three choices? And, does the match score change things much?
Difficult 5-3 on gridgammon 3 point match Quote
08-05-2014 , 03:55 PM
Results with XG roller ++

3 POINT MATCH on 0-0

23/18 8/5 best move

13/5 -0.084 (actually better than the anchor play but unplayable by normal humans like me

23/18 21/18 -0.155 (ouch!)

UNLIMITED MATCH (jacobi, center cube)

23/18 8/5 best move

13/5 -0.070

23/18 21/18 -0.141 (ouch!)

I still don't get the point doh!
Difficult 5-3 on gridgammon 3 point match Quote
08-05-2014 , 08:17 PM
I think what's confusing people here is White's racing lead (40 pips) and the fact that Black has 4 men back. Those two elements are making people think that Black is playing some sort of back game and needs to grab a second anchor, ignoring his 5-point for now.

The problem, however, is that White has no board, three stripped outfield points (13, 10, and 9) plus a big stack on his 6-point. White's going to have a hard time making the points he really needs without leaving multiple shots in the process.

Consider a quick sequence: Black play 8/5 23/18, White enters and hits on the bar-point, and Black then enters and hits one of White's blots. On this sequence Black gains back 25-30 pips in the race and now has a good board with two White checkers back. White still has nothing. In other words, Black's best game plan is just to continue making normal moves in the hopes of turning the game around and going forward. White's weak board makes this plan perfectly viable.

With that plan in mind, 8/5 is clearly the best 3, after which 23/18 puts pressure on all White's points.

If White had a good board, Black would have to play very differently. As is, the position is still up in the air, and Black should just make normal strong moves.
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08-05-2014 , 08:25 PM
Quote:
Originally Posted by yogiman
It feels wrong because you have learned about the golden five point.
That is not the golden point.
Difficult 5-3 on gridgammon 3 point match Quote
08-06-2014 , 12:25 PM
Truth is in the eye of the beholder.
Difficult 5-3 on gridgammon 3 point match Quote
08-06-2014 , 03:20 PM
Quote:
Originally Posted by yogiman
Truth is in the eye of the beholder.
Fortunately, in games like backgammon and chess, that's a completely false statement. Truth may be hard to find, but it's there.
Difficult 5-3 on gridgammon 3 point match Quote

      
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