[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
RE: [Bug-gnubg] Re: Checkerplay vs cube decision errors
|
From: |
Albert Silver |
|
Subject: |
RE: [Bug-gnubg] Re: Checkerplay vs cube decision errors |
|
Date: |
Sun, 23 May 2004 12:06:37 -0300 |
> The small effect of cube errors on overall performance allso gives
an
> interesting perspective on the so-called "pip-counting" methods.
It
> follows that for almost everyone, learning to accurately pip-count is
a
> complete waste of time.
That's a very mistaken assumption IMO. You're assuming that the
pip-count is only of use, or mostly of use, for cube decisions, and
while it is certainly an unquestionable factor, it also *strongly*
affects many checker play decisions.
For example, anchor breaking decisions are often strongly influenced by
the race, if not decided by it. Look at the position I constructed
below. Xs have just rolled a wonderful 6-3, and can choose which point
to break. Which will it be, the 17 or the 14? Well, I will look closely
at the pip-count. If I'm behind in the race, I will definitely break the
14 point:
GNU Backgammon Position ID: bBvwAQDbPcAYAA
Match ID : cAkPAAAAAAAA
+13-14-15-16-17-18------19-20-21-22-23-24-+ O: Os
| X X | | O O O O | O 0 points
| X X | | O O O O | O
| | | |
| | | |
eè[^ÉÃgtk_menu_get_active
| | | |
v| |BAR| | (Cube: 1)
| O | | |
| O | | X | ñ L
| O | | X X |
| O | | X X X X | Rolled 63
| O | | X X X X | 0 points
+12-11-10--9--8--7-------6--5--4--3--2--1-+ X: Xs
Xs: 115 pips (+14) Os: 101 pips (-14)
1. Cubeful 2-ply 14/11 14/8 Eq.: -0.303
40.0% 0.0% 0.0% - 60.0% 1.2% 0.0%
2-ply cubeful 100% speed [world class]
2. Cubeful 2-ply 14/8 5/2 Eq.: -0.387 (-0.084)
39.2% 0.0% 0.0% - 60.8% 5.2% 0.2%
2-ply cubeful 100% speed [world class]
3. Cubeful 2-ply 14/8 6/3 Eq.: -0.395 (-0.092)
38.9% 0.0% 0.0% - 61.1% 5.2% 0.2%
2-ply cubeful 100% speed [world class]
4. Cubeful 2-ply 14/5 Eq.: -0.434 (-0.131)
37.7% 0.0% 0.0% - 62.3% 4.9% 0.1%
2-ply cubeful 100% speed [world class]
5. Cubeful 2-ply 17/14 17/11 Eq.: -0.454 (-0.151)
35.0% 0.0% 0.0% - 65.0% 0.6% 0.0%
2-ply cubeful 100% speed [world class]
On the other hand, if I'm not, then I'll prefer the 17 point.
GNU Backgammon Position ID: bBvwAQDbDjAGAA
Match ID : cAkPAAAAAAAA
+13-14-15-16-17-18------19-20-21-22-23-24-+ O: Advan
| X X | | O O O O | O 0 points
| X X | | O O O O | O
| | | |
| | | |
eè[^ÉÃgtk_menu_get_active
| | | |
v| |BAR| | (Cube: 1)
| O | | |
| O | | | ñ L
| O | | X |
| O | | X X X X | X Rolled 63
| O | | X X X X | X 0 points
+12-11-10--9--8--7-------6--5--4--3--2--1-+ X: SubtleOne
Xs: 104 pips (+3) Os: 101 pips (-3)
1. Cubeful 2-ply 17/14 17/11 Eq.: +0.062
52.3% 0.0% 0.0% - 47.7% 0.0% 0.0%
2-ply cubeful 100% speed [world class]
2. Cubeful 2-ply 14/11 14/8 Eq.: +0.020 (-0.042)
50.8% 0.0% 0.0% - 49.2% 0.0% 0.0%
2-ply cubeful 100% speed [world class]
3. Cubeful 2-ply 14/5 Eq.: -0.137 (-0.199)
45.4% 0.0% 0.0% - 54.6% 0.0% 0.0%
2-ply cubeful 100% speed [world class]
In fact, the more I'm ahead, the more breaking the 17 is to be
preferred.
GNU Backgammon Position ID: bBvwAQDbBhgDAA
Match ID : cAkPAAAAAAAA
+13-14-15-16-17-18------19-20-21-22-23-24-+ O: Advan
| X X | | O O O O | O 0 points
| X X | | O O O O | O
| | | |
| | | |
eè[^ÉÃgtk_menu_get_active
| | | |
v| |BAR| | (Cube: 1)
| O | | |
| O | | | ñ L
| O | | | X
| O | | X X X X | X Rolled 63
| O | | X X X X | X 0 points
+12-11-10--9--8--7-------6--5--4--3--2--1-+ X: SubtleOne
Xs: 98 pips (-3) Os: 101 pips (+3)
1. Cubeful 2-ply 17/14 17/11 Eq.: +0.174
56.5% 0.0% 0.0% - 43.5% 0.0% 0.0%
2-ply cubeful 100% speed [world class]
2. Cubeful 2-ply 14/11 14/8 Eq.: +0.102 (-0.072)
53.9% 0.0% 0.0% - 46.1% 0.0% 0.0%
2-ply cubeful 100% speed [world class]
3. Cubeful 2-ply 14/5 Eq.: -0.104 (-0.278)
46.6% 0.0% 0.0% - 53.4% 0.0% 0.0%
2-ply cubeful 100% speed [world class]
Of course there are numerous other circumstances that can be shown, and
this is but a minor one, but it should help illustrate the importance of
the race in checker play decisions.
Albert