Backgammon Online

09-Sep-2010
02:01 PST

I am new to this game and I like the game, but I am still learning the rules, can I ask you to please tell me what is a cube offer ?. thank you

09-Sep-2010
03:05 PST

http://zooescape.com/help-answer.pl?question=31

This is ZE's FAQ on the doubling cube. (Sorry I don't know how the forum code to post links in a less clunky fashion).

Essentially, if someone offers you the cube, they are offering to double the stakes of the game, because they think they have an advantage.

If you accept the cube, the stakes will be doubled and play will continue.

If you refuse the cube, you will forfeit the game at the original (undoubled) stakes.

At the beginning of the game both players have equal control of the cube and either player can offer it at any point that they choose. However, once offered, the person accepting the double takes control of the cube and is then the only player who can (if they wish) offer to redouble the stakes at any later point in the game (at which point control of the cube would then be passed back again, and so forth...).

It can be a way of simply ending a game quickly when the outcome is obvious but it also adds an extra dimension of strategy to the game.
The trick is to offer your opponent the cube when you are confident that you can win the game but your opponent might still believe that they also have a reasonable chance of winning and will therefore accept the offer.

There is more to it, but those are the basic principles as I understand them. I'm sure that more experienced players than me might have more advice to offer or might choose to qualify some of my remarks.

09-Sep-2010
04:02 PST

Your discussion in reference to the cube is very good, but for a point of clarity I would add that in general one other point should be added. Older backgammon theory suggest that in order to drop a cube offer you believe that you have less than a 25% chance to win from any given position. Since that the doubling cube on your side gives you the chance to redouble should the position turn around. Of course the "threat" to gammon should be factored in, especially in situations where one side could be gammon-ed and the other side does not risk being gammon.

09-Sep-2010
04:07 PST

Thank you well written and understood

10-Sep-2010
21:22 PST

Though, that is for most situations. On this web site, the cube has a different value for every rating of your opponents.

Normally, when you cube a game, you are doubling either the stakes (like cash) or games. Doubling the games comes into play in a match where you play to a set number or highest number of wins.

In these two cases, the rule of 25% applies. As the common example shows: If you are offered four cubes in four games and decline all that is -4 games. If you accept all four; then win one, lose three, that is -4 games as well.

Here though, if we take two players, and run the same test we can see the difference. Say 1765 rating (player X) plays 1638 (player Y) rating. (A game I am running now.)

Y offers X the cube four times. X declines four times. At -6.75 rating points per loss, that is -27 total.

X accepts four times and wins once, losses thrice. That is -19. (values are -7.87 for a loss, 4.61 for a win)

Well, now to figure out what % of cube wins would be necessary to match the value of uncubed declines. I changed the number of games played from 4 games to 40, just a little easier to work with for me here.

If my, long neglected and forgotten, algebra holds up it would take, with cube, 3.498 (rounded) wins and 36.502 (rounded) losses to get -271.114 rating. Which meets up with the -270 rating you get from declining all 40 cubes offers.

What this all boils down to is player X can accept the cube offer if he thinks he has an 8.75% chance of winning.

And if I am playing someone close to my rating? If I am 1775 playing vs 1776. I need to win 4.375 out of 40 cubed games to come equal to 40 un-cubed losses. Or 10.94%

Now either I been having this straight in my head, or I been all wrong all along, guess i'll find out now 

---
One more thing, If you are a player that ignores rating and just looks at "combined score" on your rivals page, then the 25% rule still holds true for you.

14-Sep-2010
19:15 PST

I believe your math conclusions are on the money, but in each individual game, unlike match play your acceptance is base on the position versus rating concept. Yes the rule of thumb would be very simple. Stronger players should hold on to the cube and cube on or a roll before a knock out. Were as weaker players should be glad to have the cube in their possession as the threat to re cube and knock out a strong player often more than makes up their missing equity in experience! Note: This is much different than the "crystal ball" effect, which a stronger player would double early realizing than more times than not the position will evolve into something that the lesser experienced player would only understand much later!

15-Sep-2010
20:17 PST

Since my rating is gonna be up and down regardless. I am just gonna make everything easier on myself and predominantly focus on "Rivals" stats. So, I can stick to the 25% rule  Plus, I need to familiar myself with it anyway, for other backgammon games elsewhere.

And it gives value back to the cube after it has been cubed a couple times--instead of maxing out at 10 rating points, I can think of it as whopping them for 16-64 "combined score" points.

06-Nov-2010
19:22 PST

From their points of view (apart from Igorgetmeabrain simple and clear explanation) everybody here is right. The problem being that their points of view are wrong (from mine should I add  
The problem of backgammon, from a strategic point of view, is the use of dices, which on the contrary of chess for example, doesn't allow you to master your "trajectory". All experienced backgammon players know that, except mathematical impossibilities, EVERYTHING can happen at ANYTIME. (All players for money know the danger of the "wealthy" beginner who will accept an unacceptable cube and then roll the dices which will allow him to send you back the cube... which you will have to decline   The cube is there to oppose the omnipotence of dices by ENDING the game : better to win 1 than taking the risk of loosing 4 (if not 8). Any player at, let's say any rate above 100 $ the point, will understand that... And this a why the "big" players in the British clubs in the 70's played at very high stakes (I remember seeing games at 1000 £ the point) : because the cube seldom went above 2....