# Tag Info

14

No, the second one is not valid. There are many different rule sets for Backgammon. However, I'm unaware of any which would allow it. This quote is from Wikipedia. It is footnoted as coming from both Backgammon for Winners, and Hoyle's Rules of Games. A die may not be used to bear off checkers from a lower-numbered point unless there are no checkers ...

13

Since the edit, there are two parts to the remaining question: "When have you definitely lost?" and "How can you tell when you've probably lost?". The first is easier to answer than the second, so I'll start with that. The minimum you can roll on a go is a two and a one (note that a double one would give you four moves). The maximum is double six. So (...

8

A backgammon occurs when you have borne off ALL your checkers, and BOTH of the following are true: 1) Your opponent has at least one checker in your home area and 2) Your opponent has borne off NO checkers. In this situation, your opponent had ALREADY begun bearing off checkers when he got hit. So the fact that this checker was in your home board has no ...

7

There is no rule against a single checker hitting two blots in one turn. At backgammonrules.net (emphasis mine): Hitting blots If a player moves to a point occupied by only one of his opponent's checkers, the checker is hit. Hit checkers are forced to re-enter. This slows their owner down. The opponent proceeds - and a player ahead in the race home ...

5

These were all more or less directly copied from the source attributed at the bottom of the answer: Directly rolling a particular number (e.g. 2) 30.55% Rolling a particular double (e.g. 3-3) 2.77% Rolling a particular non-double (e.g. 5-1) 5.54% Rolling any double 16.66% Chance of getting off the bar with one or two pieces and X open points: ...

4

In your own home board it is often unwise to hit blots unless you can point on them. Leaving two blots in your home board with enemy stones on the bar approaches suicidal in all circumstances I can conceive of just now.

3

Largely it's by convention, but the historic cause is the way optimal doubling cube strategy varies with the match length. In the most easy case, in a 2-point match it can barely be wrong to double as soon as you are ahead, and far too easy to leave doubling too late - which means the match becomes a single game the vast majority of the time. In which case ...

3

The reason that equity is used instead of winning probability is because it is possible to win a single game, a double game (gammon) or triple game (backgammon). Let's say that the value of the game, or bet, is \$1. (That would occur if the cube is in the middle. If it has been turned, you multiply by 2, 4, or whatever the number is on the cube.) Let's ...

3

Just to make it an easy and fast rule, a player MUST play the larger part of the roll, if he can play ONLY one part of his dice. In the above example, if red rolls 21, he MUST play 3/1, and is not permitted to play 3/2, this is not a choice, its a mandatory move.

3

I think you are confusing two uses of the word double. If you roll doubles (e.g both dice show 3) you move not two but four counters three spaces ('Movement, 3' here). You can also use the doubling die to increase the stakes at certain times; this has no effect on the game unless your opponent chooses to resign the game rather than play for (and lose) the ...

3

The one of the biggest difference one sees between an experienced and a novice player is that the beginners hit the checkers almost without considering the alternatives. There are lot of positions where you're better off with not hitting. Just a tip to remember: Backgammon is not a game of hits, its a game of positions.

3

The disadvantage of hitting an opposing blot is that you send it to the "bar," where it will re-enter on your home board. That is a bad idea if you have a lot of loose checkers in your home board or coming home, meaning that your opponent will have a number of "retaliation" shots. It is these "retaliation shots" (if they exist), that make it inadvisable to ...

3

I'd learn the chances for the roll combinations. There are 36 possible rolls, (let's say of one red and one green die) as follows: 6-6: 1/36 11: 2/36 (two 6-5s) 5-5: 1/36 10: 2/36 (two 6-4s) 9: 4/36 (two 6-3s, two 5-4s) 4-4: 1/36 8: 4/36 (two 6-2s, two 5-3s) 7: 6/36 (two 6-1s, two 5-2s, two 4-3s) 3-3: 1/36 6: 4/36 (two 5-1s, two 4-2s) 5:...

2

You may also want to look at the following two books from Gambit Publications: How to Use Computers To Improve Your Chess by Christian Kongsted. The second half is specifically on how to use chess computers to improve our play. Secrets of Practical Chess by John Nunn The new edition has an expanded chapter on chess computers. You can download PDF ...

2

For chess there are many ways to use both chess playing programs and database programs: Play over your own games (you should always record your games, even skittles/fun games, to see where you need to improve) in "infinite analysis" mode (where the computer doesn't make moves, it just evaluates the position and finds the best sequence of moves for both ...

2

I have no sources to cite, but I think it depends a lot on your own learning style. You will certainly not learn well if the computer just tells you the best play and you follow it, but if you can carefully think through your move before being told by the computer if it's bad, and if the computer has a better move you can reason out why it's better, ...

2

Two good rules of thumb are, never resign in a position with contact, and resign if the result is "obvious". If you need to stop and think to work it out then it's probably quicker to just play on to a position of certainty anyway - certainly so online where forced moves (and optionally, greedy bearoffs) can be played automatically. It's generally not ...

2

This depends heavily on what the opponent has done so far with his runners. If both runners are still on your 1 point, or if only one runner remains in your home board, slotting forward from your 6 point often has a good risk reward. If two split runners exist in your home board (or one runner and one or more opposing men on the bar), you must be much more ...

2

Do some statistical analysis on the possible rolls: The average value of all rolls will be zero. 41.667% (5/12ths) of all rolls will be negative. 41.667% (5/12ths) of all rolls will be positive. 16.667% (1/6th) of all rolls will be zero. It seems like it would have a random walk type of effect, with no one being able to move very far (as @tttppp pointed ...

2

The chance of getting a total of x on the two dice is simply (6-|7-x|)/36 where |7-x| is the absolute value of 7-x.

1

No, as per the official backgammon rules of the US Backgammon Federation you cannot move in this instance, and your turn is over. If there is no checker on the point indicated by the roll, the player must make a legal move using a checker on a higher-numbered point. If there are no checkers on higher-numbered points, the player is permitted (and required)...

1

In The Backgammon Book, World Champions Oswald Jacoby and John Crawford recommend with both 6-2 and 6-3 moving one runner to the bar point and one man from the 12-point into your own outer table; though they concede that there another move almost as good: The modern play [written in 1970] is to use the six to move one back man to the black bar point and ...

1

Let's set a lower bound on the likelihood of winning with doubles, by simply ignoring all cases where it is impossible to win without doubles. Assumption: All board positions considered are equally likely. This is probably not true, but will approach truth in longer games. Consider the case of two men only left on the board, both in the home court, and not ...

1

Yes, Plakoto is played elsewhere - in Bulgaria, where it is called Tapa. It seems to be the same game as "Jail", described here: http://www.vitalinfocenter.com/bckgmn/jail.html

1

Sorry if My backgammon terminology is weak. If you hit a piece that's in the quarter of the board that you're trying to get your pieces to [your own home board], then you effectively set them back a few spaces less than 6. But at that point, they can potentially roll and hit one of your guys in the same quarter, which can set you back up to 20 spaces, ...

1

You should always accept a double if your winning expectation from the current situation is 25% or more. You should never accept a double when you have less.

1

You resign when it is mathematically impossible for you to win, and also, if it is mathematically impossible for your opponent to get a gammon or backgammon. This occurs after contact has been broken off between the two teams (no possibility of further hits). "Mathematically" impossible to win means, give yourself 6-6 the rest of the way, give your opponent ...

1

In professional play I can't say but if it were just you and I playing then I'd say sure you could resign just to finish the game and start a new game. Is it possible that the losing player could win ... yeah but if it's such a remote possibility then I'd call the game just for the sake of entertainment (I.E. lets play again, it's boring just to finish the ...

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