furbster:  Awesome!  I'm in the next round.  :)

a maximum of 3 more moves and we can start the second round of this tourney

LUCKY THIRTEEN

likewowman2cool:
Aganju: Thank's a lot to you both for your fast answer. I will send Fencer a notification to end the game...

speachless: Just send a message to Fencer; he will make it into a draw and end the game for you.

speachless: Yes it's a draw. I had one a while ago. The system does not recognize it, so if your opponent doesn't agree, it goes one forever...

Hi everyone... is it possible, that this game is a draw situation since both can't move further?
or is it an error?
Grasshopper (Alfredo Mendoza vs. speachless)

Merci toi aussi

Czuch: I agree with those who've stated that your opponent should have doubled at every opportunity at this match score, beginning with their very first turn.  Each opportunity they missed was a mistake.  At this point--now that they've gained just a single point--they should be thinking: "If only I had doubled sooner, and my opponent had taken!  If I'd won, I'd only have been 2 points away from victory--and that would have meant my only needing to win 1 more game, because I'll double immediately in the next game, too."

I believe that you were correct to pass when you did, Czuch.  At that point, your opponent was about a 60% favorite to win the game.  You must also consider the relatively few--but exceedingly painful--gammon losses that could instantly lose the match with the cube on 2.  All considered, it's a bit too much risk for you to be taking.  By passing, you only allow your opponent's match winning chances to creep up slightly--from 31% when this game began, to 32.26% now that the match score has reached 3 away / 1 away.  You're not sacrificing much by doing that.

Hrqls: Thanks! Anyone else got some helpful opinion?

Czuch: i think his double was a good one to offer .. and you were good to decline

he is trailing, and you only need 1 point .. so he could have offered the double on the first move in that game, but he could also wait for a position like this and hope you might accept where you should not have ..

he can hit you, and he has 1 single in his home, but so you do .. i think he is slightly the favorite ..

but dont put too much value into what i write .. i am just a beginner who plays by feeling, and not by any real analysis :)

The score was 6-3 yes... now it is 6-4 and he did make me double on the first move.... I might be regretting not accepting the double last game now :(

Czuch: Was the score 6-3 to you in that game?

Czuch: accept or decline, and after that we can discuss his and your reasoning :)

discussing wether it was a good double to offer or not also gives a hint wether it's good to accept or decline it

Czuch: Possibly he didn't notice the position. I've done that before. Forgot, and noticed a few moves in.

Czuch: I really dont mind my position in this game... he has a few open pieces and I can easily turn it around in a move or two.... but I dont need two wins, and I think it is more advantages for him to win a double than for me to lose one.... I might have even sent a double request the first move of the game if I were in his position.... why not right? So anyway... I think I will give him this one and hope he doesnt go on a dice run on me.

likewowman2cool: I was wondering if it was wise for him to send the offer.... ;)

likewowman2cool: *2*

Czuch: I will give you my answer after you choose to accept or decline the double.

Walter Montego: ~~I do not understand your programming code listed

That's not my code, that Aganju's post. Fortunately it's not necessary to understand it unless you have reason to tweak it. Most programmers treat random number generators as a black box. "Give me a random number" is all that needs to be understood.

At DailyGammon the dice generation is taken to extra lengths. The RNG uses a library routine, such as the one that Aganju showed, but it also uses physically generated random numbers from random.org, which provides values generated from atmospheric radio noise. But even then, the programmer doesn't care how the calculated numbers are actually calculated. He calls the black box for one random number, gets another from random.org and combines them. In this way, any biases in either source are removed by the randomness of the other.

~~why is it that the first number generated is not random? This was something I had a teacher tell me forty years ago. It is still the case?

It's never been the case as far as I'm concerned but my programming only goes back thirty years. Even so, I'm surprised at what your teacher said. If he was correct then the solution is as simple as you suggested.

~~why start each roll over in a game? Why not just pick say 200 numbers and store them until needed for each game.

This doesn't produce any more randomness that calculating the numbers one at a time. As it requires storage and extra programming there needs to be a distinct advantage. It would also take more time, although that's not a huge consideration on modern hardware. Whatever length of buffer you had, you'd be generating more rolls than you need and throwing the unused ones away at the end. (Using them in another game just adds more programming effort and complexity).

Aganju: ~~I think you misunderstood me. Of course, seeding every time as well as seeding only with the minutes is not a good idea; this was my try to reverse-engineer the experienced behavior here on BK.

That doesn't make sense. if you know it's a bad idea, why would you suggest it as the likely reason?

~~As I wrote below, if I play a move in five games within one minute, all my opponents have the same roll afterwards. That seems to point to
a) the roll for the opponent is made the moment I send my move, and


This is certainly the case in games with auto-pass as it's necessary to know whether or not the opponent is blocked.

~~b) the minute is used for seeding every time,
so that would explain why they all have the same roll. That's only a guess, of course, but one that explains what's happening.

I would assume a bug before considering bad programming of something so straightforward.

~~Because all my opponents answer at different times, typically this is not very obvious, but if you note it down, you can check the games and verify that they all roll equal.

I think a much better reason than positing poor programming is to suspect the data acquisition. If you've done a Masters degree then you know that it's all about evidence - extensive and methodically recorded evidence. If I were to take the claim seriously then I'd want to see what you've got.

By the way, where did you do your Masters?

Resher: I guess that would work, but I think it is a bug, and a funny one.

Aganju: Can you choose to offer a draw?  If not, then you could PM Fencer, who should be able to end the game as a draw.

I am in a Grashoppers game where bth players cannot make moves anymore (5774462), but the rules have no plan for it, and neither has the server. So we are stuck in an infinite game!

I do not understand your programming code listed PlayBunny. I think if I was going to program dice for Backgammon, I would program each die separately and then display them together. And why is it that the first number generated is not random? This was something I had a teacher tell me forty years ago. It is still the case? Well then, just ignore the first number and start on the second. And why start each roll over in a game? Why not just pick say 200 numbers and store them until needed for each game. In the unlikely event they all get used up, do it again.

playBunny: I think you misunderstood me. Of course, seeding every time as well as seeding only with the minutes is not a good idea; this was my try to reverse-engineer the experienced behavior here on BK. As I wrote below, if I play a move in five games within one minute, all my opponents have the same roll afterwards. That seems to point to
a) the roll for the opponent is made the moment I send my move, and
b) the minute is used for seeding every time,
so that would explain why they all have the same roll. That's only a guess, of course, but one that explains what's happening.
Because all my opponents answer at different times, typically this is not very obvious, but if you note it down, you can check the games and verify that they all roll equal.

A good (pseudo-)random number generator consists of multiplying a stored number with a large prime, and dividing by another large prime, the division result is stored for the next round, and the division rest is normalized to be used as the 'random' number. The quality and equal distribution of the resulting sequence depends on the choice of the two primes, and as part of my work, we analyzed all primes up to 1 billion for their resulting random number quality. I have kept the best result (I hope), and will look it up later and post it here.

I know that Fencer is rather good at what he does, and I know that a lot of people whined already about the random numbers here on BK, so I just gave up complaining myself. I just answered to someone else's comment about five times 5-5 in a row, and that it is unfortunately quite common to see that in opponents rolls if you play fast.
...

Here is the C++ code from ~2001 with the best possible random numbers for numbers below 1 billion. It will return a
double between 0 and 1, and needs to be normalized to the target interval (backgammon: 1-6).

double Rnd::Double (void)
/* Linearer Kongruenzgenerator nach Afflerbach
x[i+1] = x[i] * 27132 + 1 (mod 62748517), z[i] = x[i] / 62748517
Periodenlaenge 62748517, Beyer-Quotienten 0.969, 0.922, 0.819
Bestmoegliche Verteilung fuer Modul m <1e9 */
{
static unsigned long xi = 0;
int i;
unsigned long z = 0;

if (xi == 0) xi = (unsigned long) time(NULL);

for (i=30; i>0; i--) {
z <<= 1;
if (xi & (1L << (i-1))) z += 27132L;
while (z> 62748516L) z -= 62748517L;
}
xi = z + 1L;
return ((double) xi / 62748517.0);
}

playBunny: I enjoyed your contribution, erudite Bunny. Perhaps you should be elevated to "Play Rabbit"

Aganju: Part of my masters degree was about 'Pseudo random numbers', how to make them and how to analyze the quality. It's been a while, though.

It must have been a few decades ago if they were using the time as a seed for each random number.

Except that even then the time wasn't used to obtain each random number because you don't seed for each random number, you seed the generator once, when you first start using it.

Aganju: the routine uses the current time as seed or so. If you make many moves within a minute, all your opponents get the same roll.

So that's balderdash and gives me every reason to doubt that you studied random number generators in any depth, if at all. Generated numbers have got nothing to do with the time and everything to do with the position in the sequence which, of course, changes every time you pluck a number out. That's even assuming that a mathematical random number generator is being used in the first place, which isn't necessarily the case.

Furthermore, if some junior programmer did make the mistake of reseeding the generator before every number, they'd have to be an idiot to take the computer time - accurate to milliseconds, if not microseconds or nanoseconds, and throw most of it away just to use the minute!

Fencer, by the way, isn't even remotely a junior programmer, nor is he an idiot, although pgt's observation is, unfortunately, correct.

Um, so why couldn't I roll five double fives in a row with regular dice? It is the first time I have done it here and I play a lot of games. Seems like such a thing could still happen randomly. Long odds still happen on occasion.

playBunny: Actually, yes. Part of my masters degree was about 'Pseudo random numbers', how to make them and how to analyze the quality. It's been a while, though.

Aganju: I think the issue is that the routine uses the current time as seed or so.

Why do you think that? Are you knowledgeable about random number generators?

Walter Montego: Definitely 'luck', LOL

pgt: We should all know by now that the Brainking dice's a joke but we carry on playing regardless, all 10 of us!

AganjuNot a lot of point in discussing it here. Fencer doesn't give a stuff about Backgammon.

Aganju: Yet I would say that I don't experience your 90% stat in Dice Poker. Not even close to 90% personally

Aganju: I think the issue is that the routine uses the current time as seed or so. If you make many moves within a minute, all your opponents get the same roll. I have started to wait a full minute before re-rolling in dice poker, and it helps a lot to get a different result.

Walter Montego:
I often see that here. The discussion has been had a thousand times, and Fencer claims the dice-rolling-routine is good, but I cannot believe that.
I had nine of my opponents roll 6-6 in a row...
In Dice Poker, everybody can count this for himself: if you select two dice for re-roll, 90% of the time the same numbers come up again. Just countit or a while.

I rolled double fives, five times in a row.
Turns 16 to 20. A bit of luck, eh?
Backgammon (Walter Montego vs. *HitMan*)

Rabbits2: I just found. the rules

Where are the rules for Anti Backgammon?

Walter Montego: maybe they can now laugh about your foolish moves (not talking dancing here) ;)

Hrqls: I wonder how fun it is to play? It'd sure cut down, if not eliminate, my opponents complaining about how lucky I am. :)

i don't know if it has been posted yet, but i think i like the rules of No Chance Backgammon

read the explanation here : http://www.bkgm.com/variants/NoChanceBG/index.html

has anyone ever played it ?

HISTORY OF BACKGAMMON

Digs have exposed that backgammon conventionally was played on top of wood Backgammon History facades, by stones as pointers, and dice prepared as of bones. The ancient recognized relics supposed to have been utilized in favor of a backgammon-like game date back to 3000 B.C.

ANCESTORS OF BACKGAMMON

Senat

The earliest side of what would afterward turn out to be backgammon is the Egyptian game of Senat, recognized as Thirty Squares as well (employed date back to 3000 B.C.) small is identified on the rules of the game however the boards that have been discovered contain 3x10, 3x12, plus 3x6 squares.

The Royal Games of Ur

At what time the imperial grave of the Ur al Chaldees, the hub of Sumer, was exposed archeologist discovered wooden backgammon boards old back to approximately 2600 B.C.

Ludus Duodecim Scriptorum

The Romans named their side of backgammon Ludus Duodecim Scriptorum (The Game of 12 Lines). The game, supposed to be a straight successor to the Egyptian Senat, was taken part on top of a leather plank by means of 30 markers, 15 ebony as well as 15 ivory.

Tabula

The Romans fetched backgammon toward Northern Europe after it attacked Britain during the 1st Century. Next to the moment the game was usually known by Tabula.

Alea

Semi a millennium afterward it acquired the name Alea and began to appear progressively similar to the backgammon we play nowadays.

Nard

Near 800 A.D. a backgammon-resembling game had attained Asia plus the Persian Empire. Nard was extremely close to Alea through 2 die accustomed to shift the 30 markers.

The game too turned out to be accepted in China below the name T’Shu-p’u and within Japan where it was known by Sugoroku.

Modern Backgammon

The start of modern backgammon is marked by the introduction of the doubling cube, first used in the 1920s in New York City. In 1931 the backgammon rules were modified to what basically governs the game today.

Prince Alexis Obolensky, or "Oby", is usually accredited by means of the fast expansion of backgammon participants several 30 years ago. Oby prearranged the foremost backgammon World Championships in Bahamas.

During 1970s backgammon obtained numerous notices within the media and numerous newspapers faceted backgammon columns.

Next to the 1980s the younger invention twisted toward video games and the game of backgammon found its fame reducing.

Online backgammon

During recent years, but, that drift has been upturned due to online backgammon on web. Participants can currently discover decent rivals by each and every hours of the day just by logging on top of your computers. You can play backgammon by download backgammon from internet
The history of backgammon in two parts
Part 1: Origins
Backgammon is one of the oldest games in existence alongside Go and Chess. It is probably about 5,000 years old and may well have originated in what today is Iraq – previously Mesopotamia. Recent evidence supporting this was found when these very early dice (made of human bones) were discovered in the area:

Mesopotamian Backgammon


The board with its twenty-four points and thirty checkers (or pieces or men) has been around for a long time but the game has not always been called backgammon. Other games which used the same board were Senet and Mancala. The Romans were the first to make it truly popular with their version called “Duodecum Scripta et Tabulae” or “Tables” for short.

Frescoes in many a Roman villa depict the game in progress (the players were not always completely clothed)! Here is an example (clothed version) from Pompeii:


Pompeii Backgammon


The Emperor Claudius was a keen player – he had a special board built on the back of his chariot to relieve the tedium of long journeys. Emperor Nero was a prodigious gambler. He played for today’s equivalent of $10,000 a game. History does not record what happened to his opponents if they lost!

For many years there were different rules depending upon one’s level in society – true of many pastimes.. Whilst the officers wagered large stakes it became so popular during the Crusades that soldiers below a certain rank were barred from playing.

The history of any game can be tracked by looking for references in both art and literature. It is mentioned in early literature, both in Chaucer’s Canterbury Tales:

“They daucen, and they pleyen at ches and tables.”

and by Shakespeare in Love’s Labour’s Lost.

The word backgammon first appeared in print in 1645. No one knows for sure where the name came from, but most scholars agree that in all likelihood it comes from the Middle English ‘baec’ = back and ‘gamen’ = game.

Backgammon appears consistently in art throughout the second millennium, most famously in “The Garden of Earthly Delights” by Hieronymus Bosch and “The Triumph of Death” by Pieter Brueghel. Quite frequently it appears in tavern scenes and often there is a brawl going on - I wonder why that could be? Here it is in Steen’s “Backgammon Fight”:


Backgammon Fight


The game continued to be played throughout the latter stages of the last millennium but it had constant battles with authorities and the church who wanted to ban it because of the gambling element – not too dissimilar to some areas of the world today, particularly since America brought in its crass and ludicrous Internet gambling laws (surely they are not long for this world??)

Its popularity continued through Victorian times (see the tranquil image below) and it was very popular at country house weekend parties.


Victorian Backgammon Parties


However by the early 1920’s the game was losing its appeal. In the Roaring Twenties in New York City the games were just taking too long to play and it was difficult to wager (and therefore win) large amounts of money.
The Backgammon history (the advent of doubling)
As we saw in the previous article, backgammon was losing its appeal in the fast-paced society of the 1920’s because the games took too long and it was difficult to wager large amounts of money.

Whether the game would have survived we can only surmise but some time around 1925 or 1926 two things that would change the game forever happened at almost the same time.

The first and most important event occurred when some genius (or it may have been a group of them) in either New York or Boston came up with the idea of being able to double the stakes. We must assume that redoubling was invented at the same time and there is no contrary evidence to suggest otherwise. Sadly, despite extensive research, we do not know exactly who invented the concept so all we can do is give a heartfelt thank you to whoever it was!

The doubling cube did not arrive for some years and initially matchsticks were used to record the stakes. The first type of doubling device was a dial. An example – which I was lucky enough to buy on eBay - is shown here:

backgammon doubling dial.


This device lasted for some time as evidenced by this photo of Douglas Fairbanks Jnr. and Joan Crawford (they were married from 1929 to 1933):

Douglas Fairbanks Jnr. and Joan Crawford playing backgammon

Exactly when the doubling cube arrived is not recorded.

The second event was the arrival of the multi-player version of the game that has always been known, even in the 1920’s, as a chouette. Chouette is the French for screech owl, a bird that is set upon by many of its own kind so we can see how apt the name is! It was originally used in the card game Picquet.

Now not only could the stakes be doubled but with more players in the game winnings and losses rose exponentially! Backgammon became the perfect game for the 1920’s.

It is safe to say that doubling, whilst it solved the backgammon problems of the day and introduced a whole new level of skill, was initially very poorly understood. If you read any of the books from that era you will find some very dubious advice indeed. The basic concept of the 25% take-point was not explained in any book until Crawford and Jacoby published “The Backgammon Book” in 1970!

Georges Mabardi, author of Vanity Fair’s “Backgammon to Win” (1930) had this view of Doubling: “If two absolutely perfect players engaged in a match, there would never be an accepted double.” Close, but no cigar!

Chris Bray
Sep 07

Carl: Oh thanks a lot Carl for letting me know.... so that COULD mean that the mentioned games are saved with the missing graphics also on the Brainking-servers.... i wonder what Filip Fencer says to that...

speachless: Now I look again i see i was wrong.There is one piece missing in each example,strange.

pedestrian: you're right...

speachless: If the problem is that some image files are missing, then old games will look wrong when we play through them today. That doesn't mean they were affected when they were played.

playBunny: your links shows the same problem... missing pieces even under small sized boards... as your links are old games it means it is not a new problem but it appears already since years....

playBunny: You may have missed part of the conversation, as it started on the other board. They were already told to use small pieces to avoid it. However, this is something new, as it seems to be this way even in small pieces.

However, it would be interesting to know what is different about Carl as he has seemingly said it looks normal to him.