Page 1 of 1
Why are odd-numbered extensions the most ideal?
Posted: Sun Aug 21, 2016 9:54 am
by pocketMAD
I was watching a Nick Sibicky lecture (I forgot which), and he mentioned odd-numbered extensions are more advantageous than even-numbered ones. I'm all for implementing this in my gameplay, but I'd also prefer to know the reason for this.
Re: Why are odd-numbered extensions the most ideal?
Posted: Sun Aug 21, 2016 10:02 am
by Bonobo
Never heard of “odd-numbered extensions”
(not that that would mean anything
), but maybe you mean this?
From
http://senseis.xmp.net/?ExtensionFromAWall
Sensei’s Library wrote:For extensions from a wall, or extensions in general, the following rule of thumb applies:
From a wall, the best extension is the number of spaces of the height of the wall, plus one.
It is also embodied in the following proverb:
From one, two. From two, three.
Re: Why are odd-numbered extensions the most ideal?
Posted: Sun Aug 21, 2016 10:04 am
by Cassandra
The reasoning is the potential for creating eyes ...
$$
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . X . X . . .
$$ | . . Z , X . X . .
$$ | . . . X . X . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ --------------------
- Click Here To Show Diagram Code
[go]$$
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . X . X . . .
$$ | . . Z , X . X . .
$$ | . . . X . X . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ --------------------[/go]
Posted: Sun Aug 21, 2016 10:35 am
by EdLee
Sounds suspicious.
Re: Why are odd-numbered extensions the most ideal?
Posted: Sun Aug 21, 2016 10:43 am
by Bill Spight
Re: Why are odd-numbered extensions the most ideal?
Posted: Sun Aug 21, 2016 10:45 pm
by Calvin Clark
Side extensions from single corner stones are covered somewhat in
this set of workshop notes by Yilun Yang. In general, there is no hard-and-fast rule, as it depends on the surrounding stones, whether you seek to expand or reduce, and other tactical and strategic considerations.
Re: Why are odd-numbered extensions the most ideal?
Posted: Sun Aug 21, 2016 11:04 pm
by Kirby
The rule doesn't make sense. For example, there are several cases where a 2-space extension is great. Maybe 4-space extensions are less common, but they can happen, too.
Anyway, there is an "ideal" extension for any given situation, but this is hardly quantifiable into a rule like this.
I would say that in actual play, 2, 3, and 5 space extensions seem more common to me than 4 space extensions, but this isn't even true for mini-Chinese opening formation, where there's a 4-space extension made quite early by black.
Re: Why are odd-numbered extensions the most ideal?
Posted: Mon Aug 22, 2016 12:08 am
by Schachus
Kirby wrote:
I would say that in actual play, 2, 3, and 5 space extensions seem more common to me than 4 space extensions
I discovered a new law: "You should always extend a prime number of spaces". I'm sure 7 space extensions are great too, not to mention 11-space extensions

Re: Why are odd-numbered extensions the most ideal?
Posted: Mon Aug 22, 2016 4:14 am
by DrStraw
Schachus wrote:Kirby wrote:
I would say that in actual play, 2, 3, and 5 space extensions seem more common to me than 4 space extensions
I discovered a new law: "You should always extend a prime number of spaces". I'm sure 7 space extensions are great too, not to mention 11-space extensions

11-space extensions are usually referred to as nirensei.
Re: Why are odd-numbered extensions the most ideal?
Posted: Mon Aug 22, 2016 7:20 am
by hyperpape
I started to say the same thing as Kirby about 4 space extensions. I feel like there's something awkward to them.
Re: Why are odd-numbered extensions the most ideal?
Posted: Mon Aug 22, 2016 8:16 pm
by Calvin Clark
Pecentage of games including a 4-point extension by Dosaku as white on the 3rd line: 45/124 = 36%.
I guess confusing worked for him.
Re: Why are odd-numbered extensions the most ideal?
Posted: Tue Aug 23, 2016 5:48 am
by ez4u
Extensions from what? Otherwise this thread (and the original statement) are nonsense.
Re: Why are odd-numbered extensions the most ideal?
Posted: Wed Aug 24, 2016 2:31 am
by wineandgolover
OP is smart to ask why. He is following another famous proverb, "Beware following proverbs you don't fully understand."
Re: Why are odd-numbered extensions the most ideal?
Posted: Wed Aug 24, 2016 3:15 am
by Knotwilg
When extending, as with any move, ask yourself what you want to accomplish
- making a firm base, which cannot be disconnected but which might become overconcentrated?
- making a loose base, which can be disconnected but which allow you to move faster while sacrificing some stones?
This all depends on the circumstances, as the extension (from a wall) will also have a function towards the other side
It is better to think of moves this way then to follow rules like the one mentioned. They are restricting your thinking at best and misguided at worst.
Re: Why are odd-numbered extensions the most ideal?
Posted: Wed Aug 24, 2016 6:52 am
by Bill Spight
wineandgolover wrote:OP is smart to ask why. He is following another famous proverb, "Beware following proverbs you don't fully understand."
If I only made moves I fully understood, I would not play at all.
