I don't understand this split - Backgammon Forum - Discuss Backgammon Strategy, Clubs and Books

Two Plus Two Forums Sports and Games Chess and Other Board Games Backgammon Forum hosted by Bill Robertie.

I don't understand this split

Post Reply Subscribe

...

06-02-2009 , 05:45 PM

Chipslinger

enthusiast

Join Date: Dec 2007 Posts: 98

8/7 just seems suicidal to me, but gnub insists it's the right play...
Can someone explain this to me?
I would've played 3/2 if gnub tutor wouldn't have suggested otherwise.

Quote

06-02-2009 , 08:28 PM

djk123

Pooh-Bah

Join Date: Jun 2005 Posts: 5,069

fwiw i did a rollout with snowie and it ranks the 3 options:

8/7 -0.846
3/2 -0.851
4/3 -0.890

the first time i did the rollout i forgot to put the cube at the top and it had 3/2 as the best followed by 8/7..

Quote

06-03-2009 , 06:02 PM

Tuee

centurion

Join Date: Jul 2006 Posts: 164

I think the issue is that your only other option is to break your inner board. All the holding games and back game victories that you can win from this position require you having an inner board.

Also, his board is weak, so getting hit when you're this far behind already isn't that terrible; it puts you further behind in a race you're already losing anyway, and gives you a chance to establish a back game and/or attack his back men.

Quote

06-03-2009 , 10:22 PM

Robertie

old hand

Join Date: May 2004 Posts: 1,954

Remember that after 8/7 he has to break his anchor to hit you. The anchor is his best point, so the cost of being hit is reduced quite a bit.

The cost of leaving blots in front of points that your opponent doesn't really want to break usually isn't very high.

Quote

06-04-2009 , 01:32 AM

Aaron W.

Carpal \'Tunnel

Join Date: Sep 2002 Posts: 30,132

Quote:

Originally Posted by djk123

How much does match score influence this? Suppose that black is 3-away and white (red) is 7-away. Now black has a higher interest in simply not getting gammoned, which might influence the results.

Quote

06-04-2009 , 02:32 AM

djk123

Pooh-Bah

Join Date: Jun 2005 Posts: 5,069

Quote:

Originally Posted by Aaron W.

How much does match score influence this? Suppose that black is 3-away and white (red) is 7-away. Now black has a higher interest in simply not getting gammoned, which might influence the results.

ok, so i set the score as Black 4 - White 0 in a match to 7. is that what u meant?

3/2: -1.071
4/3: -1.098
8/7: -1.128

Quote

06-04-2009 , 03:17 PM

Chipslinger

enthusiast

Join Date: Dec 2007 Posts: 98

Thx for all the comments! I found them tremendously helpfull.
I encountered 2 similar situations today playing Gnub where the bot made a similar split and, being at the other side of it then, I more thoroughly understand the play now.

Quote

06-04-2009 , 03:20 PM

Aaron W.

Carpal \'Tunnel

Join Date: Sep 2002 Posts: 30,132

Quote:

Originally Posted by djk123

8/7 -0.846
3/2 -0.851
4/3 -0.890

Quote:

Originally Posted by djk123

3/2: -1.071
4/3: -1.098
8/7: -1.128

Thanks. This shows that the match score is having an influence on the decision.

Quote

06-04-2009 , 04:31 PM

Tuee

centurion

Join Date: Jul 2006 Posts: 164

Ok, and here's me trying in a rather specacularly bad way to apply the same principle... yeesh, i over-thought this one...

I have my theories... but... why do you guys suppose splitting the anchor on the 11 pt is wrong here?

Quote

06-04-2009 , 05:16 PM

#10

Chipslinger

enthusiast

Join Date: Dec 2007 Posts: 98

Quote:

Originally Posted by Tuee

lol, k, I'll give it a shot.
Baring one in from the 7 point does not mess up your home board, whereas the principle basically applies that if you have to choose between messing up your home board or leaving 2 blots in front of an anchor which your opponent is reluctant to break, you go for the blots because you need your homeboard to stay strong to win the game.
+ 7/6 is by far the best play, whereas in my initial post there wasn't an obvious play (and all 3 possible plays were fairly close anyway).

Quote

Post Reply Subscribe

...