3443 enclosure

Modern research

The enclosure appeared in a seemingly bizarre opening suggested by "Lizzie 0.6 loaded with LeelaZero v0.17 and converted ELF OpenGo v2 weights" in 2019, detailed by OGS 5d Mark5000 in the OGS forum thread '' ELF OpenGo weirdness.

That opening later received, in 2021, a Youtube review by EGF 3d Anton Christenson.

For what it's worth, I (bugcat, EGF 5k) made an analysis in 2020, The kosumi shimari -- the eighth enclosure?

2002-03 content

From a real game  

From a game between low-ranking Chinese pros. Black tried , making the 3443 enclosure. After the normal sequence to , you could say that Black benefits from the choice: compared with the enclosure at a, Black now has better aji here.

Drawback  

If White plays the distant low approach instead, becomes a very important play. But the enclosure on the right is worse at supporting than the 3453 enclosure at b, or the 3463 enclosure at c.

There were further experiments in the 1990s by Yang Hui, Qiu Jun and Cho Hun-hyeon.

There are examples in pro play of the corner being enclosed in the 3443 pattern during the middle game, to leave the minimum aji. For example Sakata did this in a game 1979-04-18 against Ushinohama Satsuo^[1].

This enclosure should perhaps be seen in those terms - a very tight way to take territory - despite tries to use it as an opening play.

[1] This relates on conceptual level with comments at classification of positions on the late middle game.