Hello world! Now I finally found the time to answer to Michi’s query regarding the 6-4 point. Like with normally with the questions and answers series, please write new questions as comments to this blog post!
First off, I compiled an sgf file (updated on 10 November 2011!) with some more normal variations along with my comments. The eidogo plugin in this blog doesn’t show comments for now, so please download the file (the download link is just below the plugin) for the comments.
The following, here, is for whole-board fuseki. Please check the joseki file first!
If black played double 6-4 points, for example like this, I feel that white 8 is a really feasible counter. After white 8, black can practically no longer have a big right side, which makes black 3 kind of useless. Later, if white gets the chance, he’ll take A. Black can surely make a game out of this, but it shouldn’t be so out of ordinary for white anymore.
If white plays double 6-4 points, black is simple to play as well. There are a few moves I would consider: black A is one, making white 2 rather useless again (black B later, then, given the chance). Black C instead would split the left side, not giving white 4 much to work for. Or, black could also just play his own game with D – there’s really no hurry in making the white stones useless.
As a summary, I do consider the 6-4 point playable, but it is making a player’s intentions painfully obvious (white 2 in the last figure clearly aims for the upper side, and white 4 for the left side). Personally I favor the 4-4, 3-3 and 3-4 points, which give a lot more flexibility to the follow-ups.