4-4 6-3 enclosure
This enclosure, a small knight's move enclosure from a 4-4 point, is in frequent use in contemporary go. It emphasizes territory more than the large knight's move 4-4 7-3 enclosure does.
The prime reason for saying that is the fate of the 3-3 invasion .
The 3-3 invasion here becomes ko in this main variation; though that's not the whole story.
See 4-4 6-3 enclosure, 3-3 invasion for more information.
There are a number of other standard invasion techniques:
- 4-4 6-3 enclosure 2-4 approach
- 4-4 6-3 enclosure 2-5 approach
- 4-4 6-3 enclosure second-line diagonal attachment is a position that occurs both with the 2-4 and 2-5 approaches.
- 4-4 6-3 enclosure 3-4 contact.
Also commonly used is the shoulder hit reduction:
Black's answer's at a and b both leave a little to be desired, so may (if well-timed) successfully prevent Black building a framework on a large scale here. Naturally, if Black intends to build in the centre, it would be more consistent to make the initial enclosure with a fourth line play, such as the 4-4 6-4 enclosure and the 4-4 7-4 enclosure).
After played as a pincer the exchange White a - Black b doesn't give White a proper base, so White is somewhat heavy here (position discussed at 4-4 point low approach low extension, slide, pincer, tenuki). Therefore White normally plays at one of the circled points.
Black may simply opt to take the corner with here. Later, and Endgame Tesuji 4 may be relevant followups.
If the direction of play is to favour the upper side, Black may also play at a or b.