- The title given to this article is incorrect due to technical limitations. The correct title is a3 opening.
Most players answer here g7 (+) because the center is said to be important. There are other possibilities though: i10 and j11.
Second move: i10
k10 is then a frequent move for Red, because it intrudes on Blue's template and creates a template for Red at the same time. Moreover, it may prove useful later as a ladder escape.
Second move: j11
Openings on 13 x 13 (adapted from Jonatan Rydh's page on openings)