Opening Move Variations
Ronald D. Barry
I have a question about certain opening moves that I have never seen
discussed anywhere:
It is common to play the following opening moves as shown:
62 - 24/18 13/11
63 - 24/18 13/10
64 - 24/18 13/9
Why is it not also advisable (or at least reasonable) to play them as
shown below instead?
62 - 24/22 13/7
63 - 24/21 13/7
64 - 24/20 13/7
Regards, Ron Barry.
simon
that you develop a feel for a bad position, and I know that if I played
those moves I would feel decidedly nervous as I clicked on the dice. all of
them - esp the 62 one - seem to me to hand the initiative to your opponent.
you will more likely end up playing the game responding to his/her agenda
rather than establishing your own.
Ronald D. Barry <r-ab...@ix.netcom.com> wrote in message
news:38B41EFB...@ix.netcom.com...
Mark Sproson
Looking at rolls that hit, potential rehits, covering rolls if you're
not
hit and so on, there is actually nothing obvious to point to the
generally
preferred moves - in fact if I've got my figures right (possible, though
it's late and I'm tired) Barry's move for 63 is actually 'safer' than
the
common one.
Here's the point, though (IMHO) - either play invites a very similar
blot-
hitting contest, with one crucial difference - the side of the board it
is played out on. On your side, you lose 18 pips per hit to your
opponent's
7, and you'll probably end up with more than two men at the back. I
would
guess it's a general rule that this sort of contest should be avoided on
your own side if at all possible. Anyone confirm that?
Sproz
Zuldare
mean??
dmg
| I can already feel the regret of asking this, but what do those numbers
|mean??
The numbers are a common way of describing the movement of checkers.
The points around the board are assigned numbers from 24 to 1:
+24-23-22-21-20-19-+---+18-17-16-15-14-13-+
| X O | | O X |
| X O | | O X |
| O | | O X |
| O | | X |
| O | | X |
| | | |64
| | | |
| X | | O |
| X | | O |
| X | | X O |
| O X | | X O |
| O X | | X O |
+-1--2--3--4--5--6-+---+-7--8--9-10-11-12-+
This board is seen from X's perspective, and he is moving clockwise,
so his 2 checkers on the 24 point have the farthest to travel before
being able to bear off.
Let's look at an example from the original post:
62 - 24/18 13/11
The 62 represents the roll to be played; the other numbers represent
the movement of the checkers. In this case, the poster is indicating
that the 6 will be played by moving a checker from the 24-point to the
18-point, and that the 2 will be played by moving a checker from the
13-point to the 11-point. After the move, the board will look like
this:
+24-23-22-21-20-19-+---+18-17-16-15-14-13-+
| X O | | X O X |
| O | | O X |
| O | | O X |
| O | | X |
| O | | |
| | | |64
| | | |
| X | | O |
| X | | O |
| X | | X O |
| O X | | X O |
| O X | | X X O |
+-1--2--3--4--5--6-+---+-7--8--9-10-11-12-+
If a move results in a checker being hit, this is indicated by adding
a * to the end of that portion of the move. For example, if O rolled
64 in the position above he might play:
64: 1/11*
Since it is not important whether the 6 or the 4 first was played
first, the intermediate step (1/7/11* or 1/5/11*) can be omitted. If
X had left a blot on the 5-point which O also wanted to hit), the move
can be described as follows:
64: 1/5*/11*
Note that an asterisk immediately follows the point on which a checker
is hit.
Doubles are often shown by placing the number of checkers moved in
parens after the move. For example, if O rolls 22, it could be noted
as either
19/21(2) 12/14(2) or
19/21 19/21 12/14 12/14
It's common to use the words "bar" or "off" to describe moves where
checkers are entered from the bar or taken off during bear off. For
example:
bar/24 13/9 or
5/off 4/off
Finally, it's common (though not always observed--I didn't do it in
the examples above for the sake of simplicity) to reverse the
numbering of the points when O is on roll. So the 24-point now
becomes O's 1-point, and the 7-point now becomes 0's 18-point.
Hope this helps. If I left anything out, or something is unclear,
feel free to drop me an email.
|Ronald D. Barry <r-ab...@ix.netcom.com> wrote in message
|news:38B41EFB...@ix.netcom.com...
|> Greetings:
|>
|> I have a question about certain opening moves that I have never seen
|> discussed anywhere:
|>
|> It is common to play the following opening moves as shown:
|>
|> 62 - 24/18 13/11
|> 63 - 24/18 13/10
|> 64 - 24/18 13/9
|>
|> Why is it not also advisable (or at least reasonable) to play them as
|> shown below instead?
|>
|> 62 - 24/22 13/7
|> 63 - 24/21 13/7
|> 64 - 24/20 13/7
|>
|> Regards, Ron Barry.
|>
|
Dean
("Chase" on FIBS and GamesGrid)
_______
To respond via email, replace "USERNAME" with "demiga" in my address.
Irentem
Good job on the instruction. You could be our FAQ man.
Mark
Zuldare
grief, I love it.thanks again.
dmg <USER...@hotmail.com> wrote in message
news:38b57452....@news.mindspring.com...
Chuck Bower
Ronald D. Barry <r-ab...@ix.netcom.com> wrote:
>I have a question about certain opening moves that I have never seen
>discussed anywhere:
>
>It is common to play the following opening moves as shown:
>
>62 - 24/18 13/11
>63 - 24/18 13/10
>64 - 24/18 13/9
>
>Why is it not also advisable (or at least reasonable) to play them as
>shown below instead?
>
>62 - 24/22 13/7
>63 - 24/21 13/7
>64 - 24/20 13/7
There are actually TWO general reasons that these plays are considered
inferior to the 24/18, 13/X plays. Note that 13/7, 13/X opening is coined
a "Becker Opening" because it was popularized by Bruce Becker (apparently
a 'pen name') in the mid-70's book BACKGAMMON FOR BLOOD.
Reason 1 is that splitting (moving one checker off the 24-point with
one die) and slotting (placing a checker within a direct shot of your
opponent's 24-point) is very dangerous because of the possibilty of BOTH
checker being hit (leaving few return shots). This advice ("don't
simultaneously split and slot") is from Magriel's BACKGAMMON where it is
discussed in more detail.
Reason 2 is that the slot of the barpoint on opening roll has been shown
to be a bad risk. Let's look at the two most likely scenarios:
a) the blot on the 7-point is hit (17/36 times) and 18 pips are immediately
lost.
b) the blot on the 7-point is missed and OFTEN (but not always) that blot
is covered making a valuable blocking point--the 7-point.
Is the risk (of a big pipcount loss) worth the gain (of possibly making the
7-point)? Even back in the 70's, few players stuck with the Becker Openings
for very long. Experience (and expert opinion) seemed to indicate the risk
was too great. Robots (first Expert Backgammon and then the neural nets)
confirmed this feeling.
More common alternatives to 24/18, 13/X are the simple running plays of
moving the back checker the entire roll. Here the bots (neural nets) say
24/16 is inferior (by a small, but statistically significant amount--about
0.02 units of cubeless equity) to 24/18,
13/11. The running plays with 63 and 64 are much closer. My Jellyfish v3.0
rollouts (reported in the Holiday 1997 issue of FLINT AREA BACKGAMMON NEWS)
resulted in 24/18, 13/10 being better than 24/15 by 0.008 cubeless equity
units with a statistical signifcance of ~2.7 standard deviations (estimate).
64 was even closer. Making the 2-point came in first at 0.010. 24/14 was
a close second at 0.007 and 24/18, 13/9 a close third at 0.005 cubeless
equity units. The statistical significance was less than 2 standard
deviations leading me to conclude the plays are 'equal' when JF v3.0 level-6
plays against itself.
It can be quite valuable for players to experiment with different
openings. Not only can it help one with 'offense' (making different openings)
but even more valuable with 'defense'--knowing how to play responding
rolls when your oppoent makes a non-standard opening play. And just because a
certain move is correct when a robot plays itself doesn't necessarily mean
it is best when human-A plays human(or robot)-B.
Chuck
bo...@bigbang.astro.indiana.edu
c_ray on FIBS
Daniel Murphy
<r-ab...@ix.netcom.com> wrote:
>Greetings:
>
>I have a question about certain opening moves that I have never seen
>discussed anywhere:
>
>It is common to play the following opening moves as shown:
>
>62 - 24/18 13/11
>63 - 24/18 13/10
>64 - 24/18 13/9
>
>Why is it not also advisable (or at least reasonable) to play them as
>shown below instead?
>
>62 - 24/22 13/7
>63 - 24/21 13/7
>64 - 24/20 13/7
It's good to try to use every roll to make a lasting improvement in
your position. In the opening, you have several different possible
goals -- making an advanced anchor, getting your back checkers
moving, making blocking points, diversifying your builders, etc..
These priorities often conflict, and the various rolls are variously
suitable to fulfilling different goals.
Some rolls are no brainers --- roll 31, make the 5 point -- it's yours
until the end of the game.
With other rolls, like 62, 63 and 64, it's not as easy to see which
move is best, because none of these rolls gives you much by itself --
you have to look further ahead to your opponent's reply (and your
reply to his reply) and judge, all in all, which move is most likely
to help you.
Take 64: It's 10 pips, a nice running number, but a poor roll for
making an advanced anchor or priming. So a reasonable move is 24/14.
Relatively safe (you get hit only with 2s). If you're hit, anything
can happen. If you're not hit, you've got a builder in place for
making an outside point. There's nothing wrong with 24/14.
But many players feel that 24/14 is too committal to a running game --
and consequently does not create enough tension, contact and
confusion. So an alternative is 24/18 13/9.
24/18 starts your opponent's bar point. Your opponent will miss this
blot 1/3 of the time, in which case you might anchor, hit, or move
into your own outfield. 2/3 of the time he'll it, after which you
might make an anchor, hit back, or end up with who knows what. 13/9
diversifies your outfield and prepares to make a good point. Play
after 24/18 13/9 tends to be a little sharper than after 24/14 --
resulting positions are a little more complicated. There's nothing
wrong with 24/18 13/9.
But some players feel that 24/18 13/9 is -- when either blot gets hit
-- a waste of a decent running number. So another alternative is 8/2
6/2. This play advances 2 checkers in complete safety and makes a
home board point. And it can give your opponent some headaches trying
to figure out how to respond. When you can follow up by quickly
filling in the gap on your 3, 4 and 5 points, this roll can work
wonders. But it doesn't get your back men moving, doesn't help you
make an advanced anchor, and can easily lead to prime vs. prime
positions where you -- because of that gap -- have the worst of it.
It gained popularity in recent years, but seems to be heading back
down the list now. But there's not much wrong with this play, either.
All other plays are worse than these three!
The alternative you ask about (24/20 13/7) and the alternatives you
ask about for 62 and 63 try to do too much at once and leave you much
too vulnerable to your opponent's next roll. Sure, 24/20 -- like 24/18
-- goes after an advanced anchor. And like 13/9, 13/7 starts a good
priming point. And sure, the 20 and 7 points are superior to the 18
and 9 points. If your opponent promised NEVER to hit you, this play
might even be superior to the other 3 plays I mentioned. The problem
is, that hardly ever happens. Your opponent WILL attack you on either
or both sides of the board. And even if he rolls very poorly, you'll
often have a problem deciding what to do with your next roll -- which
side of the board will you improve, leaving the other side vulnerable
-- because you usually won't be able to improve on both sides at once.
In short, compared to the best 3 alternatives, 24/20 13/7 leaves you
much more vulnerable to your opponent's good rolls and gains little if
anything when your opponent rolls poorly.
Another alternative for 64 is 13/7 13/9, a popular play for a while in
the 1970s. With this play, you keep your back checkers are safely
anchored (although still back on the 24 point) while going full steam
ahead to build a quick prime. The problem here is threefold: you'll
get hit often -- not as often as with 24/18 13/9 -- but still over
half the time; the hits are more costly to you -- you lose more pips
in the race when you're hit on your own side of the board; and you
haven't got your back checkers moving towards an advanced anchor and
better control of your opponent's side of the board. Your opponent
will hit, or make a good priming point, or bring builders down from
his midpoint in relative safety.
A final comment on 24/20 13/7: a good rule to remember (and not only
in the opening) is: Don't split your back checkers and slot in your
home board at the same time, because that gives your opponent too many
options. If he can't attack the slot, he'll attack the split. You
should view 24/20 13/7 as a kind of violation of the "don't hit AND
slot" rule, even though the 7 point is not actually in your home
board.
Try looking again at the 6 alternatives for the 3 rolls you mention
and consider: how likely is each play to work? How much have you
improved your position when they do? How much have you hurt yourself
when they don't? Spend an hour or two looking at all your opponent's
possible replies (there are only 21) and ask yourself which play you
wish you had made with your 62, 63 or 64. Tedious, I know, but well
worth the exercise.
Joe Loria
If my opponent rolls 3-1 or 4-2 I'd rather get hit than see him
make an inner board point. 1-1, 2-2 and 4-4 are great rolls
for him no matter what I did (its probably wrong for him to
use the 1-1 to hit). I'll even slot my four point with an
oppening 6-3 !
I especially like these plays if its a one point match so that
gammons are irrelevant, and back games become more attractive.
I'd rather get into a blot hitting contest than watch my
opponent build his inner board with good rolls while I struggle
with my 6-x. And yes, I know I'm losing lots of pips, but I see
this as more a game of position than a race.
I also like slotting inner board points when my opponent has
brought two builders to his outer board, in a good position
to make his 4/5/bar point. I think of this as sacrificing a
man, or diverting my opponents attention to another area of
the batttefield. Again a blot hitting contest has more appeal
to me than watching my opponent build his board. And of
course if they miss my blot, I'm in a good position to cover,
keeping pace in the inner board-building department .
wwwdotjoe in Yahoo
Ronald D. Barry
Thanks to all who provided answers to my recently asked opening move
questions, and particularly to Chuck Bower and Daniel Murphy, who
submitted clear, cogent, and thorough expositions on the strategies
involved. I also want to express my appreciation to Dean (DMG), who
explained to Zuldare the standard backgammon game recording nomenclature
far better than I could have done.
Regards, Ron Barry.