alanback: I don't really need a lesson in mathematics or statistics, I was pointing out that the ratings appear to be meaningless. Of course the more games it is based on the better, but only once the general population has reliable ratings.

I suspect in cubeless backgammon it will take years for the ratings on this site to start meaning something.

I noticed some players with high (about 2100) ratings playing 12-19 on the first move with a 6-1.

I think this proves the ratings are bogus.

These players will get trounced in a long match, which argues in favor of separate ratings I think.

The example given below was a little silly. Part of the game is to try to bear off a piece to avoid being gammoned. If you resign before going through this essential part of the game you deserve to lose the points for being gammoned in my opinion.

alanback: Problem is the current rating system renders it a little unfair having both types of games included. if a 'real' backgammon rating system is used then it weights the single games accordingly and it is a lot fairer all round.

Walter Montego: Once you use the cube you won't want to go back I'm betting.

frolind: I see... scroll down you moron.

frolind: Ok, it's not clear. How do you choose a tournament where all games in the tournament are cube matches?

For a backgammon tournament with the cube, I would suggest changing the way the tournament finishes. It should finish with a single cube match (perhaps longer) rather than a series of games, or worse yet a series of cube matches.

rod03801: Not only read them, but count the occurences of each. I recently played a 10 wins match and it isn't at all useful. Might as well hunt around for the score, which is buried somewhere on the page.

playBunny: Even if each player was in the same column all the way donw the list it would be easier, but it seems right now to be designed exactly in the way as to be the hardest to read.

All: If gammon is still possible you shouldn't be allowed resign, so it would only be an issue if you haven't borne off yet but are close enough that it is inevitable. In this case it's usually only a few extra moves.

frolind: Yes, it seems to be worded incorrectly. In fact most rules speak of the player with control of the cube, rather than in possession. This may be a translation problem, but it seems a strange way to describe it.

BIG BAD WOLF: It should be closer to the person who can double. However the way it is now you can tell pretty easily because you have the option of doubling before the dice is rolled.

In regular games on a real board it actually is necessary to have the cube in the correct place to keep track.

BIG BAD WOLF: Actually the score being more prominent applies to other matches as well. I never know the score as I can't be bothered spending the time looking for it, but in a doubling cube match it can be very important tactically.

I think it will be great in hypergammon. I look forward to the first such tournament.

I'll be glad to test, and i will play quickly.

lukulus: This is in effect for individual games I believe. This site calculates after each game, since tournaments can take years and it would render ratings meaningless if the site waited for the end to calculate.

Also in Hypergammon the top rating is 2200, and 60% of the players rated (about 300) are above 1900.

lukulus: I didn't understand that at all.

As evidenced by there being 400 players (about half) above 2000 in backgammon now, yet I'm at around 20th place with 2200.

In chess there is about 700 points between 10th and the player half way down.

This indicates that backgammon is indeed partly influenced by luck.

Hypergammon is even more bunched, considering the number of games played.

The rating system, while not the best, is not as bad as all that. Remember that the ratings have bunched up as a result of the luck in the game, and as such the expected winning %age between players of differing ratings should be accurate.

In other words if a player is still rated low with this system, they must be terrible indeed and you should lose points if they beat you.

UzzyLady: If it is as you describe it is definitely a bug.

playBunny: That doesn't make sense, there must be a point at which equilibrium is reached where players of different ability reach different ratings.

For instance if I win 62.5% of the time against a weaker opponent, we would balance out at a point where I stand to gain 6 and lose 10, whatever that difference is.

I agree in principle that this system is not good for backgammon, but the ratings would not balance to everyone equal since there is some skill in the game.

playBunny: We won't all have the same rating, since if you lose and your rating goes down, you will gain more next time you win. Since there is some skill in the game the list will still be meaningful, though not as much as another system may be.

In fact winning 65% of games against average players is the problem, and there are undoubtedly players with inflated ratings as a result (for all I know I may be one :)

Walter Montego: Actually the ratings system is now correct, assuming a game of skill of course. This will end up being fairer in backgammon as well, but still not optimal, once the ratings are recalculated.

It makes complete sense that the player rated higher risks more, and if that doesn't reflect the actual odds, then the difference in ratings is too much. This will probably be fixed somewhat when the recalc happens.

Marfitalu: That's what I do already. To be honest I rarely look at the last move of my opponent, so I doubt I'd notice.

redsales: and not only that, he used vulgarities and curses. He was probably hated by the societal elite of the day in the same way that many rap artists are today.

But back to backgammon: Since Fencer agreed to fix this (when I wonder?) I think we'd have to all agree it's a bug, right?

redsales: My point about grammar was that there is no governing body in English (unlike some other languages), yet we still have rules that everyone accepts (using a period or full stop at the end of a setence for instance).

Split infinitives was never a problem and only came about because it's not allowed in Latin and some idiots thought that was a good reason not to allow it in english. However infinitives in Latin are a single word so that's stupid.

Where would Captain Kirk be without "To boldly go"?

redsales: It's played by that rule everywhere. I don't know what you mean by not being official, by that logic you could argue English has no official grammar. All rules are arbitrary, why use only 2 dice instead of 3?

redsales: I cut and paste the rule from that site in case people can't be bothered looking (which would usually be me):

"#4 A player must use both numbers of a roll if this is legally possible (or all four numbers of a double). When only one number can be played, the player must play that number. Or if either number can be played but not both, the player must play the larger one. When neither number can be used, the player loses his turn. In the case of doubles, when all four numbers cannot be played, the player must play as many numbers as he can."

alanback: Hear hear!!!!

I stated many times the same bug, which manifested itself by making all draws count zero. Now it seems to be fixed and the ratings will be far more accurate as a result.

yay!

WhiteTower: it's because your opponent's rating is so far behind yours. unrated players actually have a hidden rating. If it's their first game I believe it's 1300.

WhiteTower: Win/loss is meaningless. Some players play the same group all the time. If 2 good players play a lot against each other that will obviously affect win/loss records.

However I agree this ratings system is a little flawed.

I actually think ratings is very important, especially when choosing an opponent.

Hrqls: I've seen this quite a lot, where I'm playing someone in 2 game, we split, and both our ratings end up higher than before. And no other games are completed between the 2 (which is the obvious thing to check first).

The explanations are not sufficient, if someone has played more then their rating would decrease and increase slower, but that doesn't explain the anomaly. Winning and losing streaks are not included in the calculation, only current rating.

So anyone have a mathematical reason why this might happen?

AbigailII: True, well stated. It was the first time it was stated though.

I haven't time to read all the posts, but here goes:

The question I answered was "So if that infinite set contains everything then what's the probablity of a given thing being contained in it?"

1, since the infinite set contains everything, so any given thing has 100% chance of being in the set.

The other confusion was around infinte games. The example of 2 pieces on each side being next to each other works like this (assuming player is on 5 spot and opp on 6 spot of his own home):

Game 1: 6-6 GAME OVER
Game 2: 1-1 1-1 6-6 GAME OVER
Game 3: 1-1 1-1 1-1 1-1 6-6 GAME OVER

etc.. infinite number of games.

The example where players continually hit each other is an infinitely long game, not an infinite NUMBER of games.

Pedro Martínez: Actually 1

AbigailII: I believe that proves an infinite game, not an infinite number of games. Small but important distinction.

playBunny: The simple case is always the best place to start, and I agree it was a clever proof.

One piece each wouldn't work, it relied on players hitting each other's block.

Well done everybody, at the start of the thread I thought I had a problem to solve, but it was already solved by the time I woke up. There are indeed an infinite number of games, as proved by the simple case with 2 pieces each left.

As for the infinitely long game, I agree with Wil. it is possible in theory to have an infintely long game. The idea that it's probability approaches zero only shows us that we have no possibility of ever seeing the game to completion. This, of course, is the point.

Wil: That is the most pedantic point I've ever heard. In that example you win the game either way, so a clarification of the rules in that situation is both irrelevant and silly.

I can't think of a bearing off example where it actually matters. Even with 2 left on 2 and 3 with an opponent blocking 1, and you roll 6-1. In this case you need to move 3-2, 2-off. But even if you move 3-off you are left in the same position, so who cares?

Perhaps we should just rename the game to Abigammon. Then we couldn't argue about the real rules.

If we are playing backgammon then this site is not the owner of the rules. The fact that the rules are shown here is only for the benefit of people who know not how to play. He has made a slight oversight here, similar perhaps to overlooking en passent in chess. It is an oversight, NOT a rule change.

I think the conversation would die if people would stop arguing in favor of the rule being wrong!!

Who cares about Baseball? This is backgammon, and there are not competing organizations that disagree on the rules. There is ONE set of universally accepted rules (as in chess - but NOT dark chess). Period.

<breath>whew</breath>

Personally I think this bug should be fixed immediately. It is a clear problem, and has a simple solution.

Until then serious backgammon players will not take advantage. Those not so serious are merely evening up the disparity in skill by a very small amount, which isn't so bad.

Andre Faria: Many people have high rantings very early on. It's the ratings I'm worried about

ArtfulDodger: I've seen this in other games as well. Could be the same person with multiple ids, especially if one or both are pawns.

redsales: it's called yahoo! That way you don't need to change email when you change ISP.

Czuch Chuckers: I see. Thanks.

Computers that surf the net are about $500 these days, monitor and all. I couldn't live without high speed having had it for years.
Never been bothered by a virus, most of them are developed by the vurus software companies I think :) I can also surf and watch TV, but of course I have to turn my head!

Back to BackGammon. Can you make the tourny 3 hours total, would that help? I would play that if the timing was right.

Is webTV cheap? What is the attraction other than that? Just curious is all, I've never seen it, or heard of anyone I know using it.

Czuch Chuckers: My mistake... thought it was one hour per move.

I can't play now... maybe next time. Signing out.