11-15 is the strongest opening move by Black as evidenced by its use 95% of the games played between experts in go-as-you-please (GAYP = unrestricted) play. Black exits from a single corner, as opposed to a double corner, which leaves the back row more vulnerable to kingship. Also, 11-15 is a move towards the board center for maximum mobility. 11-15 is so strong that more responses have been used by White to obtain equality than in any other opening. Nevertheless, irrespective of the reply to 11-15, Black has a small theoretical edge, although all result in equality with best play. 22-18 ("Single Corner"), 23-19 and 23-18 are the strongest replies, while 22-17 is only adequate. 24-20 ("Ayrshire Lassie"), 24-19 and 21-17 are inferior.

21-17, called Switcher, is a weak response and therefore not very popular by either novices or experts. 9-13 is Black's best strongest second move because it leaves White cramped at his left side of the board. This alternative, 15-19, which leaves a wedge at square 19 is more aggressive and disconcerting to an unwary White, but the resulting early removal of several pieces leads to an early draw among experts.

• 17-13 7-10
• 17-14 9-18 -> 7-11
• 22-18 7-10
• 25-21 8-11
• 26-23 19-26 -> 9-13 (wins)
• 27-23 8-12 -> 12-19
• 27-24 7-10 -> 10-19