alanback: you are right .. i didnt think of that earlier .. the TTT i played before were always unrated (although i didnt like that then, but now i see a TTT will probably decrease the bkr more than normal single games would do .. at least if someone would want to win the TTT)

joining your TTT now .. although i dont mind if it would be rated .. i like to be in a TTT with 1 big section :)

Andersp:  Assuming that a rating system can be properly designed, why do dice games differ in that respect from pure strategy games?  I don't mind losing games per se, I just would like the risks and rewards to be in balance.

alanback: i thought i would post the link to your tournament :)

Unrated Triple Gammon -- all players (up to 20)

Hrqls: The only problem I see is that players already lost giving points to their friends by resigning in a backgammon position, like in the European Song Contest.

alanback: I might be stupid but im not sure i understand your talk about unfair rating.  If you lose 12 points to a lower rated player its because he was lucky, but you have reached your BKR because of your skill, not luck?   am i correct?

joshi tm: they already did so ? hmm :(
but the same could be done in any tournament

(although in triple gammon you can do something more sophisticated, and very unsportsmanlike!, with 3 people, each player losing a backgammon to another player, giving each player 5 points for 2 games ... but lets suppose most people are fair and sporsmanlike enough so that not 3 players would conspire ? and if they did it could be caught easily ?)

Hrqls:  Thank you :-)

Andersp: reaching 2100+ can be done by luck, and with little games .. the more games you play and the higher the bkr .. the more skill should be involved .. i think ?

Hrqls:   So if i win agains someone who has 2200+  thats luck...and if he wins its skill? right?

Andersp:  I'm sure you are not stupid, just pretending to be ;-)

If I lose to a lower rated player, it may be that he or she played better than I on this occasion, or because the dice favored him or her.  Similarly, if I win a backgammon match, it may be because of the dice or because I played better.  In chess, it's almost always a matter of skill, though there can be occasions I am sure when a player with less overall chess playing ability outplays a better player. 

The point about backgammon is that the player is only partly in control, due to the random element.  Thus, a rating in backgammon is not so much a prediction about the outcome of a single match, as it is a prediction about the outcome of a large number of matches.  Given a sufficiently large sample, the luck factor will even out and the player with greater skill will win a majority of the games.

My BKR is the result of a mathematical formula being applied to the results of my games.  Some of those games were won or lost primarily on skill, others on luck.  I offer no conclusion as to the interpretation of the backgammon BKRs on this site.

I hope that clarifies it, in case you were not just pretending ;-)

Andersp: only if its against me .. ;)

AbigailII: Your logic is unfaulty ! However, things can be seen for another point of view : cubed backgammon IS backgammon, and single games are the degenerated case of matches to one point.
I take "degenerated" for its mathematical meaning, it is not supposed to be insulting to one-pointer lovers :-)

But of course you are basically right, there isn't a bigger difference between Triple and Single than between Cubed and Single.

Andersp: If you win against someone who is 2200 it means... well, not much, since the BK rating formula is inaccurate for backgammon anyway !

In any particular backgammon match, it's always possible to say that the outcome was determined by luck, since if the dice had been different the winner might have lost.  However, it's not possible to say that about 100 matches between the same players; the better player should win the majority of games, because the dice WILL more or less even out over that span.

If you belong to Dailygammon, check this tourney idea out.  The purpose is to minimize the effect of luck.

http://www.dailygammon.com/bg/forum2/main/read/18423#9

Dear everybody,



Please remember that gammons DO count in Triple Gammon tournaments.  Even though
each match is a single game, the scoring takes gammons and backgammons
into account.  Therefore, do not resign a game before you have borne
off a checker, if you have any chance of doing so.  Similarly, do not
resign if you still have checkers on the bar or in your opponent's home
table.  You will be giving your opponent points he or she may not have
earned if the game were played to conclusion.



(This just happened to me, an opponent resigned too soon.  I might have gotten the gammon, but it was not assured.)

    I notice that it is possible to create a triple anti backgammon tournament.  I'm wondering how the scoring system works in such a case.

Andersp: I think you make a valid point.

If a 1900 bkr beats a 2200 bkr, then it is called luck. If a 2200 bkr beats a 1900 bkr it is called skill.

But the better point is that a person with a 2200 bkr probably got that by being lucky themselves anyway, so doesnt it all work out in the end? On this site, at least after a person has played a certain amount of games, the person with a higher bkr is probably a better player, yet having a high bkr doesnt mean that they won all their games by skill alone either!

alanback: I would presume that you would get 1 point for a win in which you bear at least one checker off, three points for a win in which you bear no pieces off and of course 0 for the loss

gambler104:  But does anyone know how it is actually set up here?

is a backgame the way to win a game of cloning gammon ?
in normal backgammon i only go for a backgame when i am in serious trouble already ... but i see some high ranked players on here aim for a backgame from the start

in the first games against these players i didnt notice and lost .. now i notice it from the start but i am still playing it as i normally would to see what would happen

what does everyone think of a backgame in cloning gammon ?

Hrqls:It still depends on what is thrown but i find that if you have a back point then you are less likely to be blocked out and have to wait to be let back in.

One year old today. :)

(that was not a complaint, btw)

fakar10: Over a year and a half old.

AbigailII: It's hardly anti-backgammon if it's over in less than forever.

Does anyone know a quick and easy way of fixing a nackgammon mat-file from bk?

fakar10:  Fixing it in what way?

alanback: It needs an extra "move" in the beginning of each game to indicate the nackgammon starting position.

You can see examples on dailygammon. What I'm wondering is if someone has a script (I know there's some scripters among us), or another easy method of fixing it.

fakar10:  There's some discussion here:  http://savannah.gnu.org/bugs/?19084  Don't know if it's helpful.

alanback: Thanks, I'll take a look.

what is the chance of rolling a 1 ?
i think its 11/36 ?

what is the chance of rolling a 1 in 2 moves after another ? (rolling 2 1s in total)
is that 11/36 * 11/36 ?

or can i determine it this way :
(lets assume the chance of rolling a 1 in 1 move is 1/3 to make the calculation a bit easier, and ignore the rule of big numbers)
so i roll a 1 in 3 rolls, for the next move i roll a 1 in 3 rolls as well giving me 2 1's in 6 rolls .. which would lead to a chance of 1/6 to roll a 1 in 2 moves directly after another ? .. hmm .. this doesnt feel right in a lot of aspects .. but i can put my finger on it exactly :)

i am asking this because i am playing tric trac on another site and want to know what my chance is to bear off 2 pieces on the 1 position .. i think its 10/36 * 10/36 + 1/36 = 17/162 ?

Hrqls: You want to roll a 1 on two consecutive rolls? Assuming it's ok to roll a pair of 1s, then your calculation of 11/36 * 11/36 (about 0.0933) is correct. So you have about a nine and one third percent chance of rolling at least one 1 on two consecutive turns.

Remember, probability (or chance) is winners divided by total. In this case, a winner is a roll containing a 1, and you were correct that there are eleven of them. There are thirty six total ways of rolling a pair of dice.

Also, when dealing with two disjoint probabilities, simply multiply them together (as you did).

Hope that hleps.

Hrqls:

A single 1 followed by single or double 1      10/36 * 11/36 = 110/1296
Or a double 1                                   1/36         =  36/1296
Or no ones followed by a double 1              25/36 *  1/36 =  25/1296
                                                               ========
                                                               171/1296 = 13%

Hrqls: It would be 10/36 * 10/36 if all you want is exactly one 1 on each of the two rolls. But if you want at least two ones in two rolls, the chance is 1/36 + 10/36 * 11/36 + 25/36 * 1/36 == 171/1296 == 0.132. After all, you should consider rolling two 1s on either the first or the second roll.

playBunny: ah thanks!!!!
thats true .. i forgot about 0 and double or 1 and double which is also sufficient :)

thad and abigailll thanks as well! when i tought it over last night (in my head wihle lying in bed) the chance of 1/3 + 1/3 sounded very nice .. but i knew i was wrong .. in my head i also came to 17/162 by pure match .. but it had big numbers in it so i could easily have mistaken myself :)

btw i forgot about a double 6 being ok as well as tric trac will also make you move double 1 on that roll .. or 1+2 on a roll which also gives double 1 .. hmm the double 6 doesnt work as i would have to move the 6 first .. but 1+2 does work .. ok i am a bit confusing today .. i am suffering from it myself as well :)

thanks!!

A player who resigns matches or times out can change the whole outcome of a Triple Gammon tournament.

It's okay if they do it for everyone but when they only do with a selection of players it adds 5 points to the lucky ones (or the friends in the case of manipulations), whereas those whose matches with them have finished will have gained nothing, a single point or maybe 3 or only rarely, the backgammon's full 5.

Timeouts cannot be prevented but resigning matches is not an option in TTTs unless the player withdraws completely.

To prevent a player from spoiling the tournament, the TTT rules remove a player who inadvertantly or deliberately adds dollops of points to people's scores in this way. They may continue to play out the remaining games if they wish, but they and all their games are no longer part of the tournament (whether that's total removal or just not contributing to the scoring).

playBunny:  Are you saying that's the way it works here, or that it should work that way?

Because it certainly does not seem to be working that way.

alanback: There are no TTTs here. A player who resigns matches or times out can change the whole outcome ... - is how it works in the Triple Gammon tournaments. The TTT rules that I described are how that problem is dealt with in a TTT.

playBunny:  Now I understand, and I agree.

playBunny:  Playing without this rule makes it pointless to have tournaments under this format, since it will almost always be the case that someone in such a large group will time out, resign too soon, etc.  Now that you've pointed it out, I'm going to cancel the triple gammon tournament I just created recently.

alanback: Moreover, the slower you play, the better equity you have to collect points due to timeouts / resigns. It could lead people to play as slow as possible.
It could be a general rule in all tournaments that when somebody timeouts or resigns a backgammon, he or she automatically forfeits all games with maximal scores, even the already finished ones.

nabla:  That would work.

nabla: What if a player is legitimately going to get backgammoned and resigns. The system would need to handle that. Or worse yet, what if a player is likely to get gammoned, but not guaranteed and resigns. How do you score that?