I was looking over somebody's sgf collection recently and found the chinois colmez, well Pierre Colmez seemed to be noted for it. What do people think is the best way to combat this formation? Is occupying the shimari or san-san what black wants? (A or B) A play at C is presumably less efficient now? I was interested to know people's thoughts.
a White play at a is answered by Black at b and this is advantageous to Black. In the Colmez-style opening is not there and Black has a stone at c instead. Without a White stone on the right side it seems to me that if Black closes the lower right corner (so we have , , and c as in the next diagram)
then Black's position on the right is out of balance. So Black will not be in a hurry to make a shimari in the lower right, and if White can play to make Black do that it might be to White's advantage. Also, maybe this imbalance in Black's position might make it possible for White to compete in a moyo contest. But this is pretty subtle and I'm not sure if it is correct or how to do it.
Petri As I cannot contribute own thinking I blindly copy information from Yang Yilun's Fundamental Principles of Go chapter on 4-5 point. assuming 3-3 is answred as usual by a keima by B - So it ends up in 4-5
unkx80: I am likely to simply play at or c, limiting Black's expansion on the lower right side. Now Black has the trouble of deciding what to do with the lower right side without making appear in an odd position. Of course, personal opinions only.