# What is the meaning of this Joseki continuation?

In games against Leela with 7 handicap stones, Leela (white) plays the following variant of a well known joseki (knight move approach with one space pincer)

``````\$\$W
\$\$ ----------------------
\$\$ |...................|
\$\$ |...................|
\$\$ |.......X.XXX.O.....|
\$\$ |...X...xOOOX...X...|
\$\$ |......a....O.O.....|
\$\$ |..........1....X...|
\$\$ |...................|
``````

The usual continuation of the joseki I have in my books is white a. However, Leela often plays white 1 and takes me out of book here. What is the meaning of white 1 in this situation? How should black continue? Should he tenuki?

• I believe you had a small mistake in your diagram, it was one line too narrow. I fixed that.
– mafu
Sep 7, 2017 at 0:03
• I wonder if Leela likes to mix it up in in order to take you out of the book, at least when giving large handicaps; a quick glance at the site did not suggest an answer to that question. Sep 7, 2017 at 11:10
• @PJTraill In my general experience, Leela does not try out trick play (but she ruthlessly exploits any mistake of mine). Currently I am following the proverb "Your opponents big point is your big point" and I set a stone on a building up some moyo around the upper left corner. This seems to work for me. Sep 7, 2017 at 15:59
• Interesting. Of course leaving the book does not immediately qualify as a trick play, though against a weaker player (and I see that Leela is about 8 dan!) that element is more likely to be present. Good luck with your line. Does Leela go on learning when installed on your computer? Sep 7, 2017 at 18:39
• @jknappen In your line of reasoning, the key point for black is not at a but above and right of a, directly left of the 3 white stones (let's call that point x). If black a, then white plays x and black cannot block, because white would push through and atari/cut on the second line. That is why black should play at x himself and not at a.
– mafu
Sep 8, 2017 at 9:48

You should try to figure out what White is trying to do by "changing moves," as well as what White failed to do.

White failed to prevent you from moving into the center (and outflanking him) with a. That is something you should consider doing. It connects your upper side to the upper left corner stone, (and makes both absolutely safe). In a seven stone game, you should connect your groups and seek this "absolute" safety; "relatively safety is not quite enough.

Also, a threatens to seal off the left side corner, possibly forcing white to take the 3-3 point (simplifying the game in your favor).

White's next move might be a knights move kakari against your upper right corner shimari. (The meaning of his move was that he strengthened his wall. You should then "touch" with P17. After that, you have the choice of "extending" with P18, securing the corner, or (better), keeping White divided with P13, aiming at a double envelopment of White's wall.

White has "played out" two corners and gained no appreciable advantage to offset his seven stone handicap. If you can use your spear points at a and P13 to limit the influence of White's wall and keep him on the defensive, you should win quite comfortably.

W1 looks like a small mistake to me, if any. This move indirectly protects the cut at the right side, so the third line stone cannot be cut off easily. It is, however, not strongly connected. White needs to be flexible, in case the naive result (the 3 stone group) is too dangerous.

``````\$\$B
\$\$ ----------------------
\$\$ |...................|
\$\$ |...................|
\$\$ |.......X.XXX.O.....|
\$\$ |...X....OOOX34.X...|
\$\$ |......a....O1O.....|
\$\$ |..........O.2..X...|
\$\$ |...................|
``````

The keima at a would induce black to protect with a move. After that, white will enter the corner at 3-3 as soon as possible, such that white gets both influence and territory. This is a usual idea when playing this joseki.

``````\$\$W
\$\$ ----------------------
\$\$ |...................|
\$\$ |...................|
\$\$ |..3...2X.XXX.O.....|
\$\$ |...X....OOOX...X...|
\$\$ |......1....OaO.....|
\$\$ |...............X...|
\$\$ |...................|
``````

In the meantime, of course a white move at a is an important consideration. In particular white a may be almost sente against the black corner, to prevent a pincer on the right side.

On the other hand, if black cuts (starting at a), then white needs to consider if the cut off stone can lead to a new life in the upper right corner. In that case, the cut may not be that important.