redsales: Okay, so we agree that the doubling cube (especially when taken to the extreme) involves different thinking. At the more basic levels it means assigning a probability to a position, a skill which is quite dissimilar to the major one of chequer play, ranking the possible moves). At the higher levels it involves mathematics and memory (eg. remembering match equity tables).

We also agree that both the doubling cube and the castling rule introduce additional skills into their games.

So now I wonder about the degree of these additional skills. The discussion started with the idea that doubling introduces sufficient difference to warrant a separate identity.

Let's look within the backgammon arena. Hypergammon has exactly the same rules as Backgammon but has fewer men. This adds "additional skills" but I'd be hard pressed to argue that they are sufficient to claim that the thinking is different from that used in Backgammon. The tactics and strategies may be different but the thinking is still a question of ranking possible moves. Deciding that order is the same as in Backgammon but with more emphasis on probabilities and less on creating structure (ha ha, structure?). I'd say that any claim regarding additional skills can only be made in terms of emphasis rather than newness. Yet, while I can't put forward any additional cognitive functions, the game is obviously very different to Backgammon.

Considering Nackgammon we find that the additional skills argument is even more tenuous. It's almost pure Backgammon but with two men moved. Again it's a very different game, not drastically so as in Hypergammon, but still enough to give it a separate identity.

Now let's consider Chess. The castling rule adds additional skills in a quantitative way however I can't see that additional ways of thinking are required to tackle a castled king. As in Hypergammon there are new tactics involved, but no new brain function.

Chess has its nackgammons, too, with Fischer Random, Gothic, CRC. These may change strategic and tactical thinking but make little, if any, demand on new cognition. Yet these are branded as distinct variations. The different setups change the course of the game, taking the player through different areas of the game space, and that provides them with a distinctive feel.

The castling rule doesn't affect the whole game in the may that having only three does men in Hypergammon, or a different setup. Maybe that's why it's not a separate game from non-castling chess.

So where am I going with this? Well, the "additional skills" examples are almost all the same cognition but different game space. They still, however, make for separate games.

The doubling cube requires skills additional by an "order of magnitude", different cognition; doubling is pervasive, the option to double has to be considered by a player for every move while there's access to the cube; it means that a set of matches is no longer a collection of discrete games but an ordered sequence (cube decisions in later games are based on the match score). I haven't even mentioned the effect that gammons and backgammons have on the game, though they are a change that goes hand in hand with the introduction of the cube.

All of these things mean that Backgammon with the cube is a substantially different game to that without. Merely changing the position of two men has been enough to make a new variation. I suggest that doubling more than qualifies Backgammon for similar treatment.

The final point; we can elect not to have the cube in a game. In what other game is there the option to remove a complete chunk of rules and game play? Take Cylinder Chess, for example. The only difference from standard Chess is the wrap-around of the board. Can you imagine making that an option of standard Chess which players may switch on when they create a game invitation? They would both be called Chess and all games would contribute to the same BKR. You could look at a players played/won/drew/lost stats and BKR and have no idea what contribution was made by the two variations. Some players would never play the Cyclinder sub-variety, others may specialise. What would the Chess community's reaction be to that?


Given the above arguments I believe that Backgammon with the cube sharing the same identity as Backgammon sans cube has no basis in terms of the game itself. It's a pragmatic decision which keeps the number of Backgammon variations down for simplicity. There are 26 variations of Chess, only 6 of Backgammon. If we were to have doubling cube variations of those 6 then Backgammon would be in danger of catching up with Chess, especially as each new Backgammon would introduce 2 variations. [Lol, sorry Fencer, I couldn't resist that one! ]

playBunny: Nope, you're way off.

playBunny: I agree that doubling requires a different way of thinking, but in your original post you mentioned additional skills. Yes, it takes additional skills to attack a king that has the ability to castle over one that can't in the rules. This imbalance is exasperated in Fischer and CRC, where no set starting position exists, but castling and the ability to prevent it plays a far more significant role than in conventional chess. I've personally found that in CRC and Gothic/Janus chess, due to the width of the board, castling can significantly alter the course of the game by necessitating a redirection of the attack. Of course the cube requires additional skills too, but you're still playing backgammon!

frolind: Lol. I've said nothing of the sort. It's a good idea to stop; you'll be talking complete gibberish if you carry on.

playBunny: Nah, I'll stop there. Just don't make the assumption that A is not a subset of B because C is not a subset of D.

frolind: Carry on, lead me from generalities to specifics....

playBunny: Start by looking at the right sets.

frolind: Lol. Don't despair. Here's an opportunity to explain to a poor dumbo like me how one thing being a subset of another means that they are not significantly different, how the extra that the superset contains doesn't matter, doesn't serve to distinguish the two sets.

Looks like the subset thing might have gone over your head. Oh well.

redsales: Aye, castling opened up new and interesting areas of game space to be explored... but did it cause a difference in the kind of thinking that was required?

Have a look a Doubling Strategy in Backgammon and see if that bears any resemblance to the thinking involved in chequer play! ;-)

(I'm cheating slightly here. That kind of stuff is obligatory for professionals and world champions but you can get quite far with the cube without having to learn all that. It's very useful to understand the concepts involved though, even if you don't get as far as playing with the equations during a match)

playBunny: castling significantly changed the method of attacking the king in the middle vs. the flank. Also, the lack of a 2-square escape move for the king resulted in more of a disadvantage for black. That's more akin to the cube. en passant, you're right, it's not much at all.

alanback: Aye, it's worked for me in this match.

Never mind, I was confused.

I am a bit late on this, but many thanks to Fencer for the addition of the game cube ! Now I will start also playing some backgammon here.
playBunny: I agree with you. Although doubling rarely happens more than two or three times in a game, knowing how to handle the game cube probably amounts to almost 50% of the backgammon skill. In many situations it is not too hard to find the best move out of a roll by simple comparison, although you don't even know if you have 25% or 75% of chances to win. I find assessing one's chances to win much harder.

Don't double early in the game unless you have an overwhelming advantage.

A bad double:

http://brainking.com/en/ShowGame?g=1118690&i=4

Why not double early?

When you double, you surrender ownership of the doubling cube to your opponent. When you double, then only your opponent can double later. The ability to double is an important strategic advantage. You should not give up that advantage without a clear reason to do so. In money play, you should not double unless the odds are 2-1 in your favor. In match play, the doubling point varies depending upon the match score.

redsales: I'll be happy enough with the ladders too but I can't agree with likening the cube to minor additions to the moves in chess.

There might be similarities in the rationale behind their origins but after that the comparison breaks down. The cube requires additional skills. Gaining true expertise with the cube is more of a challenge that attaining the same level in chequer play, I would suggest. The en passant and castling rules hardly stretch the chess mind in a new direction.

frolind, alanback: Saying that cubeless backgammon is a subset of cubeful backgammon is the same as saying that hurdles is a subset of sprinting. It may be true but nobody thinks of them as being comparable. The are treated as separate events.

playing gammon without the cube is chronologically similar to playing chess without en passant or castling; both were introduced to liven up the game, whether for gambling purposes or not. So to further alanback's analogy, separate ratings to me would be like castling/en passantless chess vs. chess: sometimes a significant difference in game play, but in the end it's still chess. I'll be happy just to wait for ladders.

As frolind says, cubeless backgammon is just a subset of the rules of backgammon. There are many situations in backgammon where the cube is not in play. Having separate ratings for cubeful and cubeless backgammon would be like having separate ratings for chess and for chess endgames.

Czuch Chuckers: I'd like to see separate rating scales too; it would be another challenge and it would mean that the ratings are "cleaner" in as much as some people will play only with the cube while some others will play only without and being in the same rating pool makes then incomparable.

Fencer will at some stage be introducing Ladders to BrainKing. It'll be possible to have separate Ladders for chequer play and cube play.

Czuch Chuckers: The strategies for the cubeless games are a subset of the strategies for match play with cube.

I dont like the idea of not having seperate ratings for gammon games with and without the cube.... it seems like they are 2 very different games, with vewry different strategies.

grenv: Yeah, it's like a drug! You can't beat the feeling of being 4-1 down in a 5-pointer and winning gammon with a 2-cube. Better than sex, Ecstacy, crack..

(Okay, I exaggerate. It can't beat a nice cup of tea)

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

playBunny: I'd rather be able to set the game up how I want it played and let the site take care of all the details. I remember the bad blood from people forgetting or missing their gentleman's agreement about the dice usage not too long ago. It is true that I could play selected people that would honor it, but if I want to have an open tournament without the double cube and still have gammons count I wouldn't be able to stop someone from ignoring it and playing it their advantage when the time was right.

Walter: You could always agree with your opponent that neither will double.

The Backgammon rating formula values a match as 4 x Sqrt (Match length). This is then apportioned according to the probabilities of each player winning (which is calculated from the rating difference).

alanback: Do these other sites have a sliding scale to take into account these things you write about?

Is it possible to set up a series of games that counts gammons and backgammons but does not use the double cube?
That's how I remember playing the game. First one to five game points is a pretty good game.

Since I'm just trying out the double cube, I might like playing that way better after I've played it a few times. I'll have to see. In the meantime, it'd still be cool to play a series without the double cube and still count gammons and backgammons instead of the games always being valued at one point. A skunk should count extra, and that is what getting a gammon is all about. I definitely do not like the proposal of not counting the gammons in games that use the cube that haven't yet been doubled. If that comes to pass it should be an option for the game creator.

On all backgammon sites with ratings, the length of the match affects the number of points awarded for wins and losses. On the one hand, a longer match between two players of equal strength is worth more points than a shorter match between the same two players. On the other hand, a longer match between players of unequal strength may be worth more points if the weaker player wins, but fewer points if the stronger player wins. This is because the stronger player's chances of winning increase as the match length increases.

I'm thinking that the longer matches make the rating award more fair because it allows the luck a chance to even out and let the higher rated player supposedly better playing skills to make the points closer to the odds of their winning a series of games.

I've never played with this double cube, but when I did Backgammon we always counted gammons and backgammons though we didn't bet on the game. We'd usually just play first one to five game points. I'll have to get me a Backgammon set one of these days and see if I can get a game going. We usually play cards, so I doubt if it comes to pass. Least ways I still have BrainKing to play it on.

frolind: That should be the default selection.

Perhaps the final match type settings could have one more option, which could be the default selected choice: "Same as for normal rounds".

grenv: I have already been doing that in the cube tournament I create - but would be nice if by some way if it is a tournament with a cube, the default ending with 2 players will be the same since I'm sure I will forget to change the option in both places sooner or later.

grenv: At the top you specify the Match type as N points with cube. Down towards the bottom, below the time controls, you specify the Final likewise.
(It makes more sense to me that the match types go together.)

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

grenv: There are two places where you choose the match type when creating a tournament. You must choose match with cube on both of them.

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

grenv: That's already an option when creating the tournament.

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.

frolind: Those are great. For those who like life to be easy, here they are (minus Question 4 which couldn't be found):

[Q_1]   [Q_2]   [Q_3]   [Q_5]   [Q_6]   [Q_7]   [Q_8]   [Q_9]   [Q_10]   [Q_11]   [Q_12]   [Q_13]   [Q_14]   [Q_15]   [Q_16]   [Q_17]   [Q_18]   [Q_19]   [Q_20]   [Q_21]   [Q_22]   [Q_23]   [Q_24]   [Q_25]   [Q_26]   [Q_27]   [Q_28]   [Q_29]   [Q_30]   [Q_31]   [Q_32]   [Q_33]   [Q_34]   [Q_35]   [Q_36]   [Q_37]   [Q_38]   [Q_39]   [Q_40]   [Q_41]   [Q_42]   [Q_43]   [Q_44]   [Q_45]   [Q_46]   [Q_47]   [Q_48]

Most articles on gammonvillage are for paid subscribers, but the Brain Busters are free.
Here are the current Brain Busters. Type "brain busters" in the search field there (and click go) to find older Brain Busters.

Hope this is fun....

It's a set of questions posed on the Usenet newgroup rec.games.backgammon and viewable via Google Newsgroups. As such it uses text format, so the board setups are a bit awkward to read, especially as chequer movement is the "wrong" way and the home tables are on the left.

People discuss their answers but the final answer is uisually in terms of a GbnuBg rollout. For those not familiar with that it will probably look like so much gobbledegook. Don't worry too much about that; the discussions should be interesting.

Questions 1, 2 and 3
Question 4
Question 5
Question 6
Question 7
Question 8
Question 9
Question 10
Questions 11 and 12
Question 13
Question 14
Question 15
Question 16
Question 17
Question 18

Czuch Chuckers: I believe right now a 21 point cube games counts the same as a 1 point cube game.

Now don't quote me on this, but I believe it will be something Fencer will look at changing some time down the road, but it is not high on his priority list. Again, do not quote me on this since I'm not 100% sure.

Hyper Backgammon is a pretty quick game, so a 21 point cube match is Perfect for this game:

Hyper 21 - Starts November 5th

= = = = = =

Plus since some do not know how to play with the cube, some practice tournaments have been set up where NO BKR Ratings will be effected - great way to jump right in and learn.

Oct 20 - 5 Point Cube Backgammon #1

Oct 30 - 5 Point Cube Backgammon #2

How does the BKR work with these cube games? For example, if you win a 21 point match, is that worth one win as far as BKR goes?

Fencer: Thanks! Now I can stop swearing at myself for forgetting to double, just to realize that I didn't have cube access. :)

All right, I've fixed the doubling cube position. It is shown on the possessor's side which is the player who accepted the double offer.

Czuch Chuckers: yes

Sorry I am sure this was already discussed somewhere in the past 400 posts, but are games played with the double cube considered for BKR the same as with all other backgammon games?

For those of you who don't know how to play with the backgammon cube yet, I created a backgammon 5 point cube tournament where no BKR ratings will be taken - so a great way to jump in and play with the cube.

http://brainking.com/en/Tournaments?trg=11751