9-13 22-18

The opening 9-13 is called the Edinburgh. It is considered Black's weakest opening because it results in a defensive game in which he must wage a relentless and faultless defense to avoid disaster against a worthy opponent. Its weakness results from the initial move against the side of the board, which allows White to take the initiative in the center where his pieces have greater mobility. Nevertheless, 9-13 is the most popular opening among novices because of the dubious safety afforded by the board side, which can achieve success against a weak player. In spite of its inherent weakness, all attempts by experts to refute the Edinburgh, i.e., force a Black loss (a White win), have been unsuccessful and computers have proven that 9-13, like all other openings, results in a draw with best play.

22-18 is considered to be the strongest reply, although other replies, such as 24-19 are adequate. 9-13 22-18 is called the Edinburgh Single because the response 22-18 is from White's single corner.

• 5-9 18-15, 10-19 -> 24-15 -> 23-5 (wins)
• 5-9 18-15, 11-18 -> 23-5 (wins)
• 6-9 18-14 -> 23-14 -> 21-14
• 10-14 18-9 -> 26-22 (drawable)
• 10-15 25-22
• 11-15 18-11, 7-16 25-22
(wins)
• 11-15 18-11, 8-15 21-17 -> 25-11 -> 24-20
• 11-16 18-14 -> 21-14 (drawable)
• 12-16 24-20
• 13-17 21-14 -> 25-21 (wins)

Note that 9-13 22-18, 11-16 18-14 -> 21-14 is identical to 11 16 22-18, 9-13 18-14 -> 21-14.

Note that 9-13 22-18, 12-16 24-20 is identical to 12-16 24-20, 9-13 22-18.

Note that 9-13 22-18, 13-17 21-14 -> 25-21 is identical to 9-14 22-18, 14-17 21-14 -> 25-21.