I have two questions I'd like to ask Master Guo Juan.

First is what are the strengths and weaknesses of the main four shimaris from a komoku? (one space high, two space high, one space low, two space low)

And secondly I have heard many go players in the amateur ranks (including as high as 7dan with the example of Ben Lockhart in the Surrounding Game) talk about "hallucinating" in a game and missing something basic. Is there a particular method pros have for avoiding this or is it a simple case of paying attention?

All the best and many thanks for any answers on these!