Forum Archive :
Opening 6's: Slot the bar point?
> 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
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.
c_ray on FIBS
Daniel Murphy writes:
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
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.
- At different match scores (Louis Nardy Pillards, July 2002)
- Average advantage of winning opening roll (Chuck Bower, Oct 1998)
- Choosing a strategy (Daniel Murphy, June 2001)
- Early game rule of thumb (Rich Munitz, Feb 2009)
- Factors to consider (Kit Woolsey, July 1994)
- How computers play (Kit Woolsey, Mar 1995)
- Magriel's Chapter 5 (Hayden Alfano+, May 2006)
- Mloner vs Jellyfish (Kit Woolsey, Dec 1995)
- Nactating a whole game (Nack Ballard+, Jan 2011)
- Nactation (Jim Stutz+, June 2010)
- Nactation overview (Nack Ballard, Oct 2009)
- Nactation--Why use it? (leobueno+, Jan 2011)
- Opening 1's: Split or slot? (Douglas Zare, Dec 2003)
- Opening 21: Rollout (Stick, Mar 2006)
- Opening 21: Split or slot? (Dick Adams+, Dec 2003)
- Opening 32: Rollout (Stick, Feb 2006)
- Opening 43: In GOL online match (Raccoon+, Feb 2004)
- Opening 43: Pros and cons (Stick+, Jan 2006)
- Opening 43: Which split is better? (Peter Backgren+, Aug 2000)
- Opening 43: Which split is better? (Michael J. Zehr+, Mar 1996)
- Opening 51: Rollout (Stick, Feb 2006)
- Opening 52: Merits of splitting (Peter Bell, Apr 1995)
- Opening 53: Magriel's recommendation (George Parker+, July 1997)
- Opening 53: Split to 21? (Alex Zamanian, Aug 2000)
- Opening 53: Why make the three point? (Kit Woolsey+, Feb 1996)
- Opening 6's: Slot the bar point? (Chuck Bower+, Feb 2000)
- Opening 6's: Slot the bar point? (David Montgomery, June 1995)
- Opening 62: Could running be best? (Gary Wong, Sept 1997)
- Opening 62: Split, run, or slot? (Chuck Bower, May 1997)
- Opening 63: Middle Eastern split? (Mark+, Apr 2002)
- Opening 63: Slot the four point? (Dennis Cartwright+, Mar 2002)
- Opening 64: Make the two point? (William Hill+, Jan 1998)
- Opening 64: Make the two point? (Darse Billings, Feb 1995)
- Opening 64: Rollout (Peter Grotrian, Jan 2006)
- Opening 64: Split to 20? (Peter Bell, June 1995)
- Opening 64: Three choices (Brian Sheppard, July 1997)
- Opening 65: Becker on lover's leap (Jeffrey Spiegler+, Aug 1991)
- Opening 65: Computer rankings (Chuck Bower, Jan 1997)
- Opening rolls ranked (Arthur+, Apr 2005)
- Rollouts of opening 21 and replies (Alexander Nitschke, Oct 1997)
- Rollouts of openings (Tom Keith+, Jan 2006)
- Rollouts: Expert Backgammon (Tom Fahland, Aug 1994)
- Rollouts: Jellyfish 3.0 (Midas+, Sept 1997)
- Rollouts: Jellyfish 3.0 level 6 (Chuck Bower, Feb 1999)
- Rollouts: Snowie 4.1 (Rene Cerutti, Apr 2004)
- Slotting the four point (Joe Loria+, Oct 1999)
- Snowie's openers and replies (rcerutti, Feb 1999)
- Splitting versus building (Dave Slayton+, Aug 2000)
- Splitting versus slotting (Daniel Murphy, Apr 2001)
- Splitting versus slotting (Daniel Murphy, Sept 1997)
- Trice's rankings (Marty Storer, Feb 1992)