Please explain jargon
william.m.tanenbaum
to this novice?
I don't know the meaning of these three terms in the context of backgammon?
1) lose the market
2) beaver
3) equity
Thanks in advance.
--
Bill Tanenbaum AT&T Bell Labs Naperville IL.
Shuman Lloyd Lee
1) Lose the market. generically, this refers to a situation where you
wait a roll before doubling, roll a great number, and develop such a
great position that you wish you had doubled earlier when the opponent
would have taken the double, whereas now you are so strong he will
(almost) certainly drop.
If backgammon were a game such that your overall probability of winning
was a continuous function of time, then "losing the market" is a non
sequitor (as demonstrated by some early academic papers on backgammon in
_Management Science_). However, in real life backgammon, it is a
concern because of the discontinuity: from a position where you do not
"technically" have a double, you jump to a position where you are
overwhelmingly strong. If the probability of rolling such a great
number (that is, if there are enough of them) is sufficient large, then
the 'technically" incorrect double is in fact "gambling-wise" correct.
2) Beaver. Suppose X doubles Y from 1 to 2. The _unofficial_ rules
state that Y may "beaver," whereby he immediately turns the cube to 4,
and _keeps_possession_ of the cube. Generally speaking, either X has
given a very bad double (Y is actually winning), or Y is "steaming"
(he's lost his head).
There is a natural continuation of this, which is that X may then
"raccoon" to 8, with Y _still_ keeping the cube. As Lewis Deyong writes
in his book (The Playboy Book of Backgammon), "To beaver is bliss
indeed; to racoon is very heaven."
I don't know what the higher orders of this animal family are, but they
listed in Deyong's book. In most games, these higher animals are not
allowed anyway (in some games, even raccoons are prohibited).
3) Equity. This is actually a misunderstood term. It refers to your
expected value in the game, usually assuming that the value of the cube
is starting at 1 (even if there has been a previous double; simply a
normalization). For example, if I have a man on my six point, and you
have a man on your one point, and it is my roll, I will win 75% of the
time (because 27 out of 36 rolls win for me; the other 9 lose), and lose
the other 25%. My "equity" is (.75) x (+1) + (.25) x (-1) = .5.
Yes?
Dave Jones
> Could someone explain some of the backgammon jargon used in this newsgroup
> to this novice?
>
> I don't know the meaning of these three terms in the context of backgammon?
>
> 1) lose the market
To fail to double when an unskilled, loose opponent might have taken, only
to see your position improve to the point where it is obvious even to
the "customer" that he should drop.
The real disaster is when you fail to double an opponent
who would have dropped, only to see your position go into the toilet.
Some players will not double in a really strong position, hoping to come
to a weaker position which is still a theoretical drop, but more inviting.
It used to be called "Weaverizing", after a hustler who was infamous for
the ploy. The technique is of debateable merit.
> 2) beaver
An optional rule: To redouble immediately, before the doubler rolls, but
retain the cube. It is usually played by opponents who have little
respect for each other's positional judgement. Never played in tournaments.
> 3) equity
I looked it up in the dictionary. It says, "the risk interest or ownership
right in a property."
Marty Storer
: > I don't know the meaning of these three terms in the context of backgammon?
: >
: > 1) lose the market
:
: To fail to double when an unskilled, loose opponent might have taken, only
: to see your position improve to the point where it is obvious even to
: the "customer" that he should drop.
:
: The real disaster is when you fail to double an opponent
: who would have dropped, only to see your position go into the toilet.
To lose your market is to fail to double and have your position improve
to the point where you have a correct double-out on your next turn.
This is how the term is generally used, anyway--I suppose your definition
would also fit.
The term came into use when backgammon theoreticians et al. were trying
to figure out when it was correct to double/redouble. A question that
came up was, how does the probability of market-loss affect doubling
decisions? (Related questions: how big is the market loss? probability
of losing?) See Danny Kleinman's books (particularly the piece "The
Doubling Cube and Football Fields" in [I think] _Vision_Laughs_at_Counting_
Vol._2_) for a more involved discussion.
When you "lose your market," you're sorry you didn't double before your
position improved. (This is regardless of whether or not your opponent had
a correct take, if we include your definition; if we don't include it, you
only lose your market when your opponent had a correct take.) When you fail
to cash a game by doubling and then lose, either you never lost your market
(in which case you would have won by doubling later), or else you did and
never noticed.
Here's an example of Bob Eberlein's that I particularly like. It shows
that sometimes you want to double even when your probability of market-loss
seems small:
Situation: you're playing a chouette against one strong opponent and
two morons. These morons are so stupid that they'll take a cube *after*
you've won a game (assume this is legal, etc.). You're in the box,
owning the cube (no "separate cubes"; everyone's in this game).
You have one man left to bear off, on your 6 point. Your opponents have
one man on their 1 point. Should you redouble?
Your winning chances are exactly 75%, so your strong opponent can take
or drop with equal equity. Let's assume he'll want to take so that the
team will agree. Your moron opponents will take after you've won, so you
have no risk of market loss with them (assume the strong opponent is
allowed to drop separately after you've won).
If you redouble, 3/4 of the time you'll win 6 points and 1/4 of the time
you'll lose 6, for an expected value of +3 points.
If you don't redouble, 3/4 of the time you'll win 5 points (2 from each
moron and 1 from the strong opponent) and 1/4 of the time you'll lose
3 points--again for an expected value of +3 points. It doesn't matter
whether or not you redouble!
Add another strong opponent to the problem, and your correct action is
to redouble.
Play well,
Marty