On this page I'd like to discuss a tournament game of mine against a fellow shodan. In the top right corner I deviated from joseki to see what happens but also with a second agenda. In the ensuing corner sequence of 25 moves, we managed to produce no less than seven mistakes and probably more, for those seven were the ones our fallible shodan eyes saw.
What martial art has their black belts perform at an error rate of 28 % ??? This is at the same time most disturbing and very motivating. Here comes the analysis.
Pincering with
seemed to use the black thickness properly. White jumps out at
.
First mistake: is possible, but the ensuing joseki gives a strategically bad result.
White 11 at a. Black takes territory but there is aji in the captured stones, namely when White gets a stone at the circled points. If at b instead, White c gives Black a feeling of Overconcentrated shape. Of course, this error is not nearly as grave as the blunders that are to come. Black still has a game.
Second mistake: entails a local loss, but in fact it is consistent with my hidden agenda: push through at a. So, not such a bad mistake after all. However, if
now at b, her territory will be superior to Black's influence.
Third mistake: works locally but also increases the corner aji and Black will now cut at a more effectively (see later). At the time of the game I thought
did not work and I drew out my stones, which is actually good because of the aji.
correctly states that she will capture the corner.
Diagram 2 shows how Black gets the most out of this position.
is best.
creates too much aji for her to stretch. Black then plays kikashi at
and gets nice outward thickness.
Fourth mistake:
does not work. Diagram 3 shows why. Moreover, there is less aji in this stone.
at
. This becomes a two-stone edge squeeze.
White wins the capturing race by one liberty.
( at
)
Sure enough White makes a fifth mistake and now Black has his chances. See Diagram 4:
is tesuji. Whatever White tries, after
she has to protect the cut at a, upon which Black gets ahead in the capturing race with b.
Sixth mistake: Black chooses the wrong 1-2 point. Luckily, he has still his chances. See Diagram 5:
The first-line hane of enables Black to get ahead in the capturing race, or get an overall advantage, or take everything in ko. See Diagrams 6, 7 and 8.
at
,
at
Black links up and will most probably capture one of White's groups. The only resistance White has is diagram 8:
( at
,
at
,
takes ko at
)
So early in the game, there is no ko (there are no ko threats in the opening).
Seventh mistake: Finally, I decided not to take any risk any more and forewent the first line hane. I pushed through at and up to
I obtained substantial central thickness in exchange for a big corner. Numerous blunders would follow however, eventually leading to a well-deserved loss.