Why are odd-numbered extensions the most ideal?

[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.

[Bonobo]

Never heard of “odd-numbered extensions” (not that that would mean anything ), but maybe you mean this?

From http://senseis.xmp.net/?ExtensionFromAWall

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.

[Cassandra]

The reasoning is the potential for creating eyes ...

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[EdLee]

Sounds suspicious.

[Bill Spight]

And then there is Lockett's Law: http://senseis.xmp.net/?LockettsLaw

[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.

[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.

[Schachus]

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

[DrStraw]

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.

[hyperpape]

I started to say the same thing as Kirby about 4 space extensions. I feel like there's something awkward to them.

[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.

[ez4u]

Extensions from what? Otherwise this thread (and the original statement) are nonsense.

[wineandgolover]

OP is smart to ask why. He is following another famous proverb, "Beware following proverbs you don't fully understand."

[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.

[Bill Spight]

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.