WhiteTower: I can't agree. Ratings are a much more accurate indicator than won-lost, because they take into account the strength of your opponents. This is not to say that the rating system here couldn't be improved!

AbigailII: Are you looking for an infinite number of finite games, or an infinite number of unique finite games? The method you describe will produce some duplicates.

playBunny:

Maybe we have to use one of those other infinities. How many are there? ;-))

Guess ;-)

Chessmaster1000: My math degree is 36 years old so I'm too rusty to be sure of this . . . but I think that, while an infinite sequence of random rolls would certainly contain any *finite* sub-sequence (indeed, an unlimited number of such sub-sequences), I don't think it's correct to conclude that it will contain any given *infinite* sub-sequence . . . at least if the infinity in question is the infinity that measures the number of integers (referred to I believe as aleph-sub-naught).

Pedro Martínez: The probability that I or anyone else will roll 55 forever is zero.

As White Tower suggests, the laws of probability do not apply to infinite sequences. They are meaningful only in the context of a finite sequence.

Pedro Martínez: Since you will never be able to roll forever, why would you want to know that?

Pedro Martínez: The probability that an infinite sequence of random rolls will include a sequence of N consecutive double fives approaches 100% . . . where N is an arbitrary integer.

Pedro Martínez: more correct to say it approaches 100% -- since the probability of completing an infinite series in finite time is zero ;-)

AbigailII: Why can't you move the 4 first? You could move 7-3, 3-off or 7-3. 4-1.

grenv: I wouldn't say there is one set of universally accepted rules; indeed, there are many local variations. I have a friend from Persia, which might claim to be the birthplace of backgammon, who has educated me on the rules used in that country. However, there does appear to be only one set of rules used in international tournaments.

So far as I know there is no set of local rules that allows a player to use only one die if there is a move available for both, or to use only the smaller die when there is a move available for the larger; but it would not surprise me if such a set of rules existed. Nevertheless, I think Fencer's intention was to apply the rule set applicable to international tournaments.

It's clearly a matter of individual conscience whether to follow those rules, when the server allows moves that violate them. In the past, I've waffled on this point, sometimes taking the position that my following the international rules strictly gave an unfair advantage to unscrupulous opponents. Lately, I've chosen to do what makes me most comfortable, which is to follow the international rules and forgo opportunities to take advantage of what I see as a glitch rather than a "house rule".

Hrqls: It seems odd at first, but you get used to it, and I appreciate the way it speeds up play.

Hrqls: Trailing 2-away at Crawford you have only about a 30% chance of winning against an opponent of equal strength. Therefore, when you are doubled at 2-away, 2-away you should accept the cube unless your winning chances are less than 30%.

Hrqls: I think I have noticed that a 3-wins match counts the same as a single game win -- is that correct? Seems like it should count for more.

WhiteTower: The DG formula seems to work more smoothly, if nothing else. It's supposed to be the same as FIBS.

Dailygammon Ratings

grenv: Your observation seems to be correct as long as the opponent is within 400 points of your rating. If the difference is greater than 400 points, then you will be penalized heavily for losing while gaining very little if you win. This is why I try to limit my opponents to those within 400 points of my rating.

Mike UK: Do you understand the two rating systems well enough to explain the differences? I thought they were basically the same, but clearly they are not.

danoschek: Thanks for pointing that out, I can hide that crazy German character now ;-)

playBunny: The observation I referred to was statistical -- I can't prove it, but the point was that any history more than 400 experience points old had little effect on your rating -- I think we have all experienced how ratings can swing. If you've been winning recently, your rating is relatively high; if you've been losing, relatively low; it doesn't matter much what it was this time last year. This is different from the 400 points needed to get past the "newbie" factor, of which I am also aware.

pgt: Certainly worth considering. For those of us with paid subscriptions, it would not be a hardship; but Pawns who play a lot of different game types might find it hard to keep up.

pgt: I've heard it said that on FIBS, your rating is pretty much determined by your most recent 400 experience points anyway. So, why not base ratings on that?

My pet peeve on this site is players who achieve a ridiculously high rating in just a few games (I still don't understand how the rating system allows that to happen) and then just sit there refusing to play more games. I have had a challenge outstanding with the #1 ranked nackgammon player for months with no response. He is not obligated to play me, but I think he should be obligated to play someone and defend his position. A very high rating based on a limited number of games is not an accurate indicator of ability in any case. Some system should be devised to prevent players from sitting forever at the top of the ratings without playing. Perhaps they could be moved back into provisional status if they don't finish a game in a given timespan (such as two months).

THE HIT MAN: My eyes may be going bad, but sometimes I swear the dice change in the course of a move. I will read them as 3-2 but after the first click they are 3-3. Since the numbers are always similar, I assume it's my own eyesignt or inattentiveness, but maybe something like that is happening to you also.

We could get this good a discussion going about backgammon!

Pedro Martínez: You meant to say in each case -- "approximately" ;-)

My 2000+ variants tourney is ready to go, except there is one more place in the 8-player field for Crowded Backgammon -- who will get there first??

Really shows how unaware of my surroundings I can be, since I spent 4 weeks in London last fall without noticing that miles were still "standard" in the mother country. Of course, I did nothing but walk around the City and go to the office. I did learn to look to the right before crossing the street, at least.

playBunny: My apologies. I was under the apparently mistaken impression that Britain had gone metric :)

danoschek: Well, there is a certain geographical factor -- miles are standard in the US, but just about nowhere else. If you wanted to speak of an international standard for measuring distances, you would refer to the metric system. Similarly, the rules which are used in international tournaments are "standard" for that very reason. It's not that they are better than other rules; some rules had to be picked, and these are the ones. "Standard" does not mean "best", it means "most commonly used or accepted" - and that is not a subjective matter but a matter of objective fact. This is why I qualified my statement be referring to tournaments only -- in casual or money play, the rules are what you make them, and there is no standard.

Another test for whether a rule is "standard" is whether you are expected to follow it without prior agreement. Most people who play for money in the US use the Jacoby Rule. In some clubs, Jacoby rule is "standard" so that if you sit down to play and don't agree otherwise, the rule is in force. This often takes me by surprise, since in my home club Jacoby was not followed unless the players agreed upon it in advance.

There is no standard without context -- "miles" is a standard unit of measurement, but only in the US. Similarly, in international tournaments, we play backgammon by the accepted international rules, including those that allow "fiddling"!

danoschek: Except for a few remaining glitches, and with the notable exception of the doubling cube, the rules played here are the standard international tournament rules.

Vikings: No mention of that rule at the following rules site: http://www.bkgm.com/variants/AceyDeucey-American.html

However, I'm willing to bet that there are many, many variations of acey-deucey that can claim legitimacy. There is no international standard for acey-deucey as there is for backgammon, I don't think.

danoschek: If it's that popular, then it would be nice to see it here as a variant. We would need a full writeup of the rules, of course.

danoschek: OK . . . I understand at least partially. That is not a standard rule, of course. Although it does remind me of what I was once told about the way the game is played in Persia.

danoschek: But what do you mean by the topmost triangle?

Suppose both players are bearing off. I have 2 checkers remaining on each point in my board. I roll 6-1. Under standard rules, I can bear off two checkers, from the 6 and the 1 point. Are you suggesting that should be illegal?

danoschek: I still have no idea what you mean. You can already swap the dice to use them in the order you choose; there is a glitch on this site which allows a player to use the smaller of two dice, if either but not both can be used; also, to use one die in such a way that the other cannot be used, even though there is a move available that uses both. Is that what you are talking about?

Are you suggesting a rule that allows bearing off only from the highest possible point? (Or that you can't bear off from a point if a higher point still has checkers?) That is not a standard backgammon rule, at least not in the international game.

Kannst du es auf Deutsch erklären?

danoschek: Got any more of that stuff you'd like to share with the rest of us? It might make it easier to understand you :-)

What is this backgammon thing you keep rattling on about?? ;-)

grenv: Just like you just did?

Walter Montego: Autopass is not a rule, but a convenience. Naturally during over the board play, a player does not roll when he could not possibly move. In that situation, if we wished to double at any time, he would simply say so before the opponent's next roll. When programming for this siutation, it would be desirable to give the opponent who is shut out the opportunity to double (if that option is available to him under the rules and is meaningful) or to resign. It might be possible to give a player the option of checking a box to forgo those options in a given game or in all games.

jahaja: I remember when one of the highest rated human players on FIBS had the username onepointer because he only played one point matches. Knowing the fine points of checker play is like knowing the fine points of chess endgames: necessary but not sufficient to make one a well-rounded player. Adding the doubling cube is like adding a third dimension (anybody ever read Flatland?). And by the way, folks who have not played with the cube before would do well to read up on cube strategy before venturing into ratings land with the cube for a guide.

The cube is a relatively recent addition to an ancient game. Still, it's all backgammon today
I also agree that the cube should be an option, not a new type of game.

I would love to see the doubling cube used here, but please don't call the resulting game "Pro" Backgammon -- it's just backgammon, plain and simple. The game without the cube might be called "Amateur" backgammon, but that's another issue. Please don't import the ridiculous ItsYourTurn terminology here!

I just took a look at penteman's unfinished games, about the first 15 are sure losers. Well, that tarnishes his accomplishment a tad ;-)

Pedro Martínez: What is that, 23 straight wins? That strains even my credulity. However, a day of reckoning will come :)

We have a new ratings king -- but for how long? ;-)

wayney: Not the best, just the one with the highest current ranking :-) good game!

wayney: It's shaping up as an interesting game. Too late to break the streak, though!

wayney: Thanks -- I was lucky against some very able opponents!

I said I had a winning streak and I gained 62 points -- did not mean to imply any cause and effect beyond the fact that all the rating adjustments were positive.

Chessmaster1000: No bonus for a streak.

Chessmaster1000: No mystery. If you win several games in a row, your rating goes up more than if you win some, lose some . . . It also helps that I have been playing some excellent players, including yourself!

Winning streak update: 13 straight over 8 days, a 62 point gain and first place!