Diagram 1: Last week, we looked at how territory is surrounded, increased and defended. However, to avoid too much confusion we started with a pattern in which the first few stones were already played. But how do you develop your positions to get the right mix of strength, flexibility and efficiency?
As shown in Reference 1, the easiest place to make territory is in the corners, followed by the sides and then the center. Stones are usually played close to or on the black accented 4-4 points in the corners. In the diagram, black 1 and white 2 are adjacent to two of the points, black 3 in on the third point and white 4 has been placed diagonal to the fourth point.
Black 5 is easy to understand--it encloses the corner. The corners are now occupied. White could have made a corner enclosure, or shimari, at 7 next, but white 6 builds a position between Black's corners. Black 7 prevents a shimari and white 8 starts the first battle.
Reference 1: The black groups A, B and C each surround nine points of territory. Seven stones are needed in the corner, 11 on the side and 15 in the center. The white groups D, E and F surround four points each. They need five, 10 and 11 stones, respectively. Which is the most efficient group?
Reference 2: During the opening stage, the moves A through E (in order of popularity) are usually played on a 19-by-19 board. The moves F and G are also sometimes seen. The mirror images of these moves have the same local value that is B is at the 3-4 point and naturally the 4-3 point has the same value.
Diagram 2: Black 1 is the most popular move. However, it doesn't take the corner territory. Even adding a stone at A or B does not completely secure the corner--an extra stone at C would be needed to accomplish this. In general, Black's aim is to stake out a larger framework toward the sides, for example with an extension to D or E.
Diagram 3: Black 1 is also played frequently. It aims to enclose the corner with any of the moves A through D (again, in order of popularity). If the marked stone is present, black E is a popular follow-up, aiming at further expansion with a move in the neighborhood of F.
Diagram 4: Playing on the 3-3 point with black 1 used to be very popular 50 years or so ago, but it is less so now. Recently, however, some top pros have started to favor it again. The advantage over the other moves is that it secures the corner territory. Moves at A and B are good points for expansion, combined with moves at C or D, or at E or F.
Diagram 5: Black can also play at 1 as a first move in the corner. This move aims at A next. and then at B or E to enclose the corner. But rather than doing this, Black often extends to C or D in an attempt to prompt White to invade the corner at A in order to start a fight.
Diagram 6: Black 1 has similar intentions as in Diagram 5. However, it is even more center-oriented. Follow-ups are A through C to make a shimari, and D or E to make an extension first and provoke a fight in the corner when his opponent invades.
Solutions to last week's problems
Solution 1: In this game, White played mane-go (mirror go), i.e. he imitated all of Black's moves. With the combination 1 through 5, Black can finally break through this pattern and score a point in the center.
Solution 2: Both Black and White should be aggressive in expanding their own territory while preventing the opponent from doing the same. The moves shown may not all be ideal, but they are good enough for our purpose: getting an idea of which moves are significant and which are otherwise. Want to find out more? Come to Ben's Cafe in Takadanobaba, Tokyo (03-3202-2445 or www.benscafe.com), where the English-speaking go community congregates every Sunday. You can enjoy free lessons, 11 a.m.-1 p.m.
Rob van Zeijst is a four-time European go champion and European representative at the Fujitsu World Championship.