Tommie wrote:My view is that I do not know of any objective argument pro or con.
There are two very good reasons why Black should never play a diagonal Fuseki. One is a social reason and the other is pertaining to the strategic idea of direction of play. One, in books, the diagrams are always presented from Black's view, as a courtesy to the person studying the game (who is assumed to be taking the black stones). There are a few assumptions here; one, that White is usually a stronger player and receives 0.5 komi, versus 6.5 komi as in an even game. Therefore what is being shown here is proper play; if Black deviates from this proper play, it is regarded as either rude, because Black is telling White "I am stronger than you, I don't need the knowledge of studying" or hopelessly naieve (Black is telling White "I have not studied this game.") Which is also considered rude, since then how could you have appeared before such a White?
But brushing all that aside, it's also a classic direction of play mistake. Moving in the opposite corner is bad shape for the same reason the elephant jump is bad shape compared to an ikken tobi. Perhaps it is more easily understood with this example:
$$W Two direction of play mistakes, or three?
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . X . . . . |
$$ | . . . O . . . . . , . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , d . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . c . . . . . . . . . . . . . 9 . . |
$$ | . . . . . . . . . . . . . . . 4 a . . |
$$ | . . . O . . . . . b . . . . . X 3 . . |
$$ | . . . . . . . . . . . X . O 8 2 1 . . |
$$ | . . . . . . . . . . . . . . 6 5 7 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------
- Click Here To Show Diagram Code
[go]$$W Two direction of play mistakes, or three?
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . X . . . . |
$$ | . . . O . . . . . , . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , d . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . c . . . . . . . . . . . . . 9 . . |
$$ | . . . . . . . . . . . . . . . 4 a . . |
$$ | . . . O . . . . . b . . . . . X 3 . . |
$$ | . . . . . . . . . . . X . O 8 2 1 . . |
$$ | . . . . . . . . . . . . . . 6 5 7 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Regardless of the moves beforehand, it is easy to see that when Black blocks at 5 it is in the wrong direction of play.. when White extends to 9, it's the same sort of feeling as in the diagonal fuseki; black's group on the bottom does not have a clear way of connecting to his stone in the upper right. White is happy with this because his two stones on the left can 'see' each other. They have some mojo going on, but not so for Black.
On the other hand, were Black to respond to White's initial approach move simply at 'a', it would be a better direction for his stones since then White would not have such an easy time of it on the right side; any waruichi (wedge) would be attacked. On the other hand, after Black's extension at 'a' and White's settling at or around 'b', Black will still be left with a good approach move at 'c'.
Therefore we might even question Black's pincer response as a poor direction of play. And in that light, certainly, also the diagonal fuseki.
As an aside, White's original approach move can also be criticized because it allows black to extend towards his shape on the top right; for this reason you will often see players making a waruichi (wedge) around 'd'.
Now, where did I hear this? Gee, I can't remember. But I'm pretty sure a pro told me.
ganbarimasu!
is good for black. So I play this way:
