After looking at Mao Jiajun’s picture (below) for many times, I finally begin to get sick of her face and look at her board position instead. It appears to me that she is considering a joseki position that is quite popular nowadays and I recall having watched a lesson (a 30 minute lesson on this variation of the joseki alone) in one of those Baduk tutorial CDs produced in China and hosted by Wang Yuan, 8p. I have therefore, for the benefit of those interested to know more, transcribed the lesson onto a sgf file. If you have not played this variation of the Hoshi joseki before, learn this and go destroy your rival the next time you play at the club. Heh heh….
Answering White 4 at A is one common joseki and has been used since the olden times. After Black answers at A, White will extend to B.
However, as Go research progresses, it is normal for Black to not play at A immediately and reserve the choices.
In the future, Black has the choice of playing at A if he/she wants later. Black also has a choice to pincer at C and let White play at A and then seal White in at D.
Black can also play at E if he/she needs to develop the center-right.
By not answering White 4 at A immediately, Black has gotten himself/herself the above mentioned options, a valuable flexibility.
Another interesting response Black has is to play at F. This move was first used by Go Seigen and is popular in more recent Go, especially among the Korean professionals. This variation, as seen in Mao’s game below, will be our topic of discussion.
Note: Because I use the free version of the hosting service on the web, it disallowed my uploading of a .sgf file. As such, I have to use the Yahoo! Briefcase but it disallows public sharing because I am also using the free service. So you will need to be a Yahoo! member to download the file. If all fails, please let me know and I will e-mail the file to you.
Edit: If you still cannot download via the link above, please try here: http://rapidshare.de/files/13169183/hoshiVariation.sgf.html