Why lower points better in blitz?
Fredrik Engel
>A blitz is a postion where one side is caught on the bar without an
>anchor, and his opponent rushes to close him out. A successful blitz
>will normally win a gammon or BG. Once 'committed to the blitz' the
>attacker should not care much about the 'purity' of his position. This
>means that deep points are as good as high points in his board. Deep
>points may even be better because the holes in his board will then be
>high and easier to reach with his following echelons of attackers.
(from a Fredrik Dahl posting)
This has been mentioned several times by very strong players, and I can't
agree with the reson stated above. How can the higher points be easier to
reach? No matter how you move, you have the same pipcount. (At least before
the bear off) So If you have made your lower points, you have used more
pips to get there, so therefore your other checkers are farther back. To make
higher points you dont have to use so many pips, so therefore your other
checkers are more advanced. So therefore it doesnt matter which points you make
in that respect. (Then there are lots of other arguments of course, most
concerning how you stand if the blitz fails)
But it cant be easier to make another point if you have made your lower points
instead of your higher.
Am I wrong?
FME on FIBS
==> There is no cure for birth or death save to enjoy the interval / Santayana.
Daniel Murphy
On 16 Jul 1997 09:19:16 GMT, d3e...@dtek.chalmers.se (Fredrik Engel)
wrote:
I think so. I think you're simply counting pips rolled and checkers
moved from the starting position. That's not relevant.
What's relevant is the exact position of the checkers during the
blitz, especially the checkers you have in your outer boards, and your
limited choices for constructively using the particular rolls you get.
You might easily have a position where you can either make a high home
board point, but leave no direct covers for a low one, or make a low
point, and leave yourself a direct cover (or more chances to cover)
for a high one.
______________________________________________________________________
Daniel Murphy San Francisco, California rac...@cityraccoon.com
Online Backgammon:
http://www.fibs.com, telnet://fibs.com:4321
In San Francisco, monthly tourneys, annotated games:
http://www.backgammon.org/bgbb/
sund
--1--2--3--4--5--6-------7-8--9-10-11-12--
| o o o | | o o x |
| o o o | | o x |
| o o | x | o |
| | x | x o |
| x x | | x x o |
| x x x x | | x x o |
|24-23-22-21-20-19 | |18-17-16-15-14-13---
If o is to move a 3-1 at this point.
It is a lot easier to make the 5 pt later if he makes
the 3 pt now, than it is to make the 3 pt later if
he makes the 5pt now.
Fredrik Engel seems to be be confusing the way we arrived
at a position with the analysis of what to do from the
position we have arrived at.
Yes, if we hadn't wasted those pips making the 2 pt earlier
we'd have lots of builders for it now. However, ...
'from _this_ position' we have a better chance of making
the 3 and 5 pt fast by making the 3 pt now.
FE refers to that the playability of the position achieved
in the event the blitz fails. That's part of the fun, of
course. In the above game, obviously we'd prefer to hold
the 5 pt if the blitz crumbles.
Is he wrong? No, just arguing the wrong point, I think.:-)
jerry su...@netshop.net wren1 to some
Fredrik Engel <d3e...@dtek.chalmers.se> wrote in article
<5qi3mk$cqf$1...@nyheter.chalmers.se>...
Stein Kulseth
In article <5qi3mk$cqf$1...@nyheter.chalmers.se>, d3e...@dtek.chalmers.se (Fredrik Engel) writes:
|> >the holes in his board will then be
|> >high and easier to reach with his following echelons of attackers.
|>
|> agree with the reson stated above.
I'm not a very strong player, but I throw my 2 cents in anyway. Here's
an example: O has two checkers on bar, only showing X's side of board:
X X X X X | |
X X X X X X | | . . X X X X
X has a four to play, and can either move one of the outside checkers
(12-8 preferred) or move 6-2. After 12-8 6's 7's 8's and 9's cover the
blot on 2 (21 numbers) but after 6-2 in fact all 36 numbers cover.
While the pip count is the same we see that moving the outside checker
moves this one checker closer to the hole, whereas swiching inside moves
the hole closer to *all* outside checkers, thus it is easier to reach.
(think also about it this way, a high hole can be reached with a lower
total pip count than a deep one, thus it is easier to reach).
There's also another important aspect, suppose O hits the blot, and
get's an anchor. If you have brought your checkers around and just want
to bear in and win you don't want to contain O, you just want to
move past him as easily as possible. This is easier if he has a high
anchor than a low one. This does not apply in every blitz position though,
in situations that are still complex, you might still want containment
if O should anchor, but you should consider this when deciding whether
or not to switch inside points in a blitz.
--
stein....@fou.telenor.no - http://www.fou.telenor.no/fou/ttkust
Michael J Zehr
Here's a concrete example about making low points:
X X
X X X
X X X X X
1 2 3 4 5 6 7 8 9 10 11 12
O has two on the bar, X to play a 41. [Match score is such that gammons
count for X.]
X can make the 2 or the 5 pts. If X makes the 5pt, X has no rolls that
make a point next turn. If X makes the 2pt, X has 44 and 64 to make the
5pt.
Also, after making the 2, X has 5's, 7's, and 9's to hit loose on the 4
point (22 rolls) and 4's, 6's, and 8's to his on the 5 (29 rolls).
After making the 5, X has 1's, 9's and 11's to hit loose on the 2 (18
shots) and 7's and 9's to hit on the 4pt (11 rolls). (There's more
duplication here than in the above counts as well.)
Against this huge difference in rolls that make points or attack, making
the 5pt is better if O rolls an entering double, or if O anchors
eventually. (However, although the 5pt anchor is much better for O, O
has greater chances of anchoring on the 2 than on the 5, so it tends to
even out. O can probably take a double after an entering 55, but not
after a 22, depending on the match score. But this is only a few
games.)
At the table, you don't need to go through the exercise of all this
counting. All you have to remember is that by making the 2 instead of
the 5, you're bringing ALL your other builders 3 pips closer to one of
the remaining open points. Put a builder on the 10pt and it becomes
even more of a difference making the 2pt instead of the 5pt.
-michael j zehr
Brian Sheppard
Fredrik Engel <d3e...@dtek.chalmers.se> wrote in article
<5qi3mk$cqf$1...@nyheter.chalmers.se>...
> >A blitz is a postion where one side is caught on the bar without an
> >anchor, and his opponent rushes to close him out. A successful blitz
> >will normally win a gammon or BG. Once 'committed to the blitz' the
> >attacker should not care much about the 'purity' of his position. This
> >means that deep points are as good as high points in his board. Deep
> >high and easier to reach with his following echelons of attackers.
>
>
> reach? No matter how you move, you have the same pipcount. (At least
before
> the bear off) So If you have made your lower points, you have used more
> pips to get there, so therefore your other checkers are farther back.
Good point about the pip count, but you have missed something important.
Let's define "blitz count" as the number of pips minimally needed to
close the inner table. If you have N open points, blitz count equals
the sum of the nearest 2 * N men, minus the sum of the pip counts of
the open points.
Your point is that the blitz count is not reduced by switching points,
and that is quite correct. If you move a point lower you do not advance
the men in the outer table, so the blitz count is exactly the same.
But there is a lot more to it, because the blitz count is a somewhat
abstract view of blitzing. After all, the blitz is not like a race.
A blitz is like a race where you have to throw the exact numbers to
bear off. That is harder than it looks, and blitz count is not the
ideal tool for analyzing blitzes. Let's take some examples.
First, you cannot necessarily move a particular number outside, due
to enemy points. Small doublets are particularly prone to blockage.
The option of switching points is very useful since the blitz count
is reduced even though the outer-board pip count remains the same.
Second, the crucial issue isn't really the pip count, but the number
of builders directly bearing on a point. If you move a 3 by playing
5/2, covering a blot on the 2-point at the expense of leaving a blot
on the 5-point, then you might add builders on the 9, 10, and 11 points
to the list of covering numbers. If you kept the 5-point instead and
moved one of the builders, then the best you could do is to add one
builder to the list of covering numbers.
Third, you often need to bring around more men than are minimally
necessary to cover the open points. A builder might be hit, for
instance. Or you might have to accumulate several builders before
you throw the exact number to close a point. Suppose that you need
to bring 3 men around in order to close 1 point (instead of 2 men).
If you advance an the open point you reduce the outer board
component of the blitz count by 3, not 2. Thus, advancing the open
point does reduce the time needed to close the point.
Fourth, high-points can be "pick-and-passed." That is, if the opponent
enters a man, you can hit him and then lift the blot to safety. This
tactic is not available on lower points, since there is no place to
safety the blot.
Finally, rememer that the crucial goal of blitzing isn't to close
out the other guy, but to buy loads of time to bring your men around.
This purpose is often well-served by a 5-point board. If the opponent
establishes an anchor high in the board, that poses no problem provided
that you can bring your men inside while he is still on the bar. In fact,
the ideal 5-point board would leave the 6-point open, since that allows
the most pick-and-pass plays, and it is the easiest anchor to bypass.
Brian