cherryhill wrote:first, it just seems like the first diagram covers a lot more territory and that the second gives white a lot of room for an extension. otake talks about how if you don't play the marked black stone in the first diagram you are asking for trouble but it seems like the 2nd diagram doesnt play this stone yet is better for it?
Did you read the whole Principle-Six-chapter to the end?
Because in diagramme 5 and in diagramme 7 and onwards Otake explains the weaknesses of the high corner enclosure (it deals more with the high Shimari enclosure but the principle is quite similiar).
As fas as territory is concerned, the high corner enclosure in this diagramme offers not per se more territory but has a lot more potential than the low corner enclosure.
$$Bc a to c or common invasion points.
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$$ | . . X , . . . . . , . . . . . , . . . |
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$$ | . . c . . . . . . . . . . . . . . . . |
$$ | . . . b . . . . . . . . . . . . . . . |
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$$ | . . . X . . . . . O . . . . . , . . . |
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- Click Here To Show Diagram Code
[go]$$Bc a to c or common invasion points.
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$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O O X . . . . . . . . . . . . . |
$$ | . . W , X X . . . X . . . . . , . . . |
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$$ | . . X , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . c . . . . . . . . . . . . . . . . |
$$ | . . . b . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . . . . . . |
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cherryhill wrote:second, the second diagram, it assumes (literally in the text, it goes, IF white 2 & 4 then the exchange is over and white is solid) white will follow the joseki, which it doesnt in the first diagram. there is an earlier principle that discusses the possibility of white doing what it does in the d1 by not following the joseki but by extending to the star point. there is no discussion about what might happen if you respond to the approach with the knights move like in d2 and white doesnt respond with the standard joseki. here it just seems like two different scenarios with different variables are being compared where in the first white is being difficult but in the 2nd white isn't. it makes it harder for me to see the benefit.
You should focus on Black's position for the moment.
To clarify first the "third is for completion" and "the fourth line is for developement" thingy: If you look at diagramme 5 in in this chapter in Opening Theory Made Easy you'll see what Otake means with Black omiting the third line extension would be painful for Black. So to complete his position Black needs to make an extension from his fourth line stone (extension = development) to the third line (third line = completion).
But this extension is of low value because White is strong and low on the top, so despite Black making locally the right move, it just defends and has very little impact on White (e.g. no attack) or Black's further game (no follow-up, the stone offers no possibilities). A move that serves just one purpose and above all if this one purpose is only defending, then the move is generally speaking not very efficient.
Moves, especially in the opening stage, should aim at a follow-up, they should have more meaning in them.
With this in mind, White does not want to exchange D2 for C3 as in your second diagramme. It will only solidify Black unneccessarily (it adds more stones to Black's position, so it ought to become stronger ^^) and White would like to keep all his options. Since Black already played a inferior variation, White should be patient and see how he can get the most of this. E.g. which point a to c he will play later on.
cherryhill wrote:third, i have read this chapter a few times... besides believing (because i do) the idea, theoretically, that the 4th line is for development and the 3rd is for completion, i don't understand it based on the examples given. i don't see for instance, why the marked black stone in d1 isn't "completing" the shape by being on the third line as it is. it seems like according to the principle it should be completing something since its on the third line. i just don't understand whats wrong with it and why it isnt completing territory, roughly, as it appears to be.
No, you understand it just fine. But the example goes a little bit deeper than that. The extension to the third line in you diagramme 1 does complete Black's shape, but see above it has very little value in itself.
So Otake says, it is much better to play on the third line (third = completion, no further move neccessary) immediately (your second diagramme) when White approaches because an extension along the side is not big but when Black plays high it is urgent otherwise White will approach again and Black's stones are floating (see Otake's diagramme 5).
In a nutshell: A stone on the fourth line not only aims to make an extension (development) to the third line, it also requieres it to a certain degree (see again Otake's diagramme 5). But at the same time if you have to make an extension to complete your shape, this extension should have more meaning than just having to defend/complete a fourth line stone. This is about efficiency (see Otake's diagramme 3 and 4).
I would recommend you read this chapter again, because I think Otake actually answers all your questions =)
, or the one with 
:
) that will make the first extension worth making ( 
).