buggnubg - Bugs: bug #42820, Use of doubling cube error

 
 

bug #42820: Use of doubling cube error

Submitter:  None
Submitted:  Mon 21 Jul 2014 09:53:50 PM UTC
   
 
Originator Name:  Mark Originator Email:  * -email is unavailable-
Item Group:  Other bug Category:  Other
Release:  * 1.01-Release Privacy:  Public
Operating System:  Windows 7 Severity:  3 - Normal
Open/Closed:  Closed Assigned to:  None
Priority:  5 - Normal Status:  Invalid
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Fri 25 Jul 2014 02:14:03 PM UTC, comment #5: 

Thanks for taking the trouble to reply and explain this.  Clearly, it is my understanding of the game that is in error, not the software.  Sorry to have troubled you.

Anonymous
Wed 23 Jul 2014 02:47:00 PM UTC, comment #4: 

Howdy. As a beginner the cube can be one of those things that requires some experience getting use to. In your attached example the computer correctly dropped. You are nearly 70 pips ahead and have him pretty much trapped. When you cube your opponent you give them the chance to drop (give up the current value of the cube) or to take. If your opp take the cube is then doubled.

In your case the cube hasn't been turned yet (value of 1). You cube and your opponent drops conceding just the 1 pt. One of the reasons it did drop is that you are so far ahead and you have a lot of gammon chances. The computer knows this. So it is giving you one point when it knows you have a good chance for 2 points.

Consider what would happen if the computer took your cube. You'd be playing for gammon on a 2 cube (in your situation). If you gammon the computer it will lose 2 times the value of the cube or 4 points. 4 points is a lot to potentially lose in a position you are favored to gammon from. So instead of risking 4 the computer gave up the game by dropping and got away with only losing 1 point.

If you have really good gammon chances, which you know you do in this case - you don't want to cube the computer (or a good opponent). You play on to get your 2 points rather than letting your opponent get off the hook with 1 point.

This type of position is what we call "Too Good to Cube". It is better to play on than to allow the opponent to concede.

Michael Petch <mdpetch>
Group administrator
Wed 23 Jul 2014 02:10:55 PM UTC, comment #3: 

Just tried again - same thing happened, this time I've taken a screen shot (attached).  Thinking I was on for a Gammon, I tried to double, and Gnu promptly refused and ended the game.  This time the cube was on 1, previously it hasn't been.  Either way, would have expected it to play on.

Looking at it from the other side, if I was in that position and tried to concede to a single point, Gnu may well have refused and played for the Gammon, surely?


Anonymous
Tue 22 Jul 2014 09:01:13 PM UTC, comment #2: 

Yes, I am a beginner, using a thin book, a website that shows some basics (Ladbrokes!), and your program.

When it looks clear that I can expect to finish the game with the opponent not having all the discs back in the final quarter and "baring off"(I'm pretty sure that is a Gammon and worth more than one point), and I try to double, instead of either agreeing or declining (and playing the game on, giving me the prospect of a more than a single point), it ends the game, giving me a single point.  The only time it hasn't done this was when I was in a poor situation early in the game, and Gnu doubled.  I accepted (didn't know you could refuse until your reply by the way!), then I got lucky and the game turned around.  When I was clearly about to win, I tried to double, and the game ended immediately and I got 2 points (it was already doubled).  I was therefore denied the chance of getting Gammon, doubled.

I thought that was either a bug, or Gnu was cheating (!)  because, if I look like losing, it often doubles, and I accept (as I said earlier, I didn't know you could refuse...).  There's no option that I can find for me to end the game and give Gnu a single point when I'm getting stuffed and about to have a Gammon against me!

Hope that clarifies what I was getting at - if it's my misunderstanding of either rules or software, sorry for having wasted your time.

Anonymous
Tue 22 Jul 2014 07:23:24 PM UTC, comment #1: 

Maybe there is a misunderstanding about what doubling implies (you write you are a beginner, are you a self-taught beginner, starting more or less from just a write-up of the rules ?).

Anyway, when you double, the game doesn't necessarily continues with the stakes doubled. You propose to do this, but your opponent can accept (when he thinks his position is reasonably salvageable) or refuse, giving you one point (if he thinks it is too desperate).


Philippe Michel <plm>
Group administrator
Mon 21 Jul 2014 09:53:50 PM UTC, original submission:  

Although I am a beginner, I think this is a bug.

The release is "Version GNU Backgammon 1.02.000-mingw 20130728", but that was not on the drop down menu.

When playing a game and towards the end, if I'm winning and looking like getting more than a single point win (rare event!), if I try to double, it doesn't do that - just gives me a 1 point win (multiplied by whatever the cube value is currently).

Anonymous

 

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Attach Files:
   
   
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Attached Files
file #31763:  GNU screen shot.png added by None (931KiB - image/png)

 

Depends on the following items: None found

Items that depend on this one: None found

 

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    Follow 3 latest changes.

    Date Changed by Updated Field Previous Value => Replaced by
    2014-07-27 mdpetch Open/ClosedOpen Closed
        StatusNone Invalid
    2014-07-23 None Attached File- Added GNU screen shot.png, #31763

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