Markus: I get your point, but I do not fully agree. Lets take the area O2-Q1. W plays Q2, and B gets 6 points, no more moves in that area possible. Nobi: Best defence is Q2. Now: If B gets to play there first: 5 points. But if W plays first, B should answer at O1 (if P1, W has Q1 as sente). Even if W leaves it like this, and B could play later Q1, B has 3 points. Otherwise 2. In my opinion "considerably" is justified.
Farkas: The lower the level of a problem, the bigger margin of error is acceptable. At this level q2 is just as acceptable as s1.
The lower the level of a problem, the bigger margin of error is acceptable. At this level q2 is just as acceptable as s1.