Subject:	BIG GAME 2 Answer
From:		John Fairbairn <JF@harrowgo.demon.co.uk>
Date:		Tue, 22 Apr 1997 22:12:21 +0100

Do you remember how often your schoolteachers told you to read the question before answering your exam papers? There's been a little touch of not-reading all the available information here, I'd say. I speak smugly of course with the benefit of foresight as well as hindsight (a pretty heady mixture, I can tell you), having seen the game and the comments.

No-one seems to have chosen Kudo's Black 15, but that's no surprise as it was a new move. Several people latched on to the three alternatives he mentioned, but as I stated in my follow-up hint, far too many were far too preoccupied with the top side.

The available information that everyone seems to have forgotten is that Black said he was punishing White 6 by playing Black 7. That means he is concentrating on his right side moyo, not the top. And White 10 and 12 were intended to advance out into the centre to erase this moyo from a distance.

Before explaining Kudo's moves, for the benefit of the weaker players let me try to explain what is going on in macro terms.

Black is building a moyo. In almost all moyo games the moyo builder would love to tempt the other side to invade it soon. He will then attack the invade and *** let him live small *** (no need to kill) and in the process build a strong wall that lets him secure the rest of the moyo as territory, like an oyster creating a pearl around a tiny piece of grit. Rash invasions into moyos like this tend to turn two thirds or even three quarters of the moyo into territory.

However, you never see this in pro games. Instead, the other side will try to build up strength at a distance so that he can invade later and live not so small. That is what White is trying to do here with his centre group.

Black of course is trying to keep White off balance by attacking him relentlessly. If he can do this well, he will not only retain sente but will build up strength in front of his moyo, and this is a secondary way of turning the moyo into territory.

It becomes a bit tortuous, but Black will never rely on turning his moyo into territory and he will be prepared at any time to let White invade and live if, in the process, he can attack the invader to get strength to attack elsewhere. You will see all these points in this game.

The top side is no man's land - what the Japanese call horse pasture, land too poor to grow rice on. If you try constructing various scenarios there, you will see that neither side can get much territory there in relation to the number of stones they have to invest (at least this early in the game).

Now to the pro bit.

Kudo played 15. q13.

He mentioned q14 as a possibility, the move that springs to mind first. But he quoted against it the sequence that Jan van der Steen spotted (see diagram):

White peeps at p15, forcing Black q15 and can then turn to j16 in good order with his weakness covered. He gets the lead in the attack (next is Black l14, White l13, Black k15).

Kudo then considered r14, with the idea of avoiding giving White a forcing move to cover his cutting point. He said it was also possible to play p14, a move that several rggers spotted (he didn't give variations - I think you are supposed to realise that it is not the tactical nuances that matter as much as concentrating on the right side).

But he decided to try something different with q13. His thinking was this: if White peeps at p15, fine - Black will answer at q15. White can still turn to the top side to attack (in order to get a strong centre group, remember) but Black will have made a gain on the right side because then the stone on q13 is in a better position than a stone on q14 would have been. This sort of analysis is called tewari and is a big feature of professional opening play.

When asked by a _very_ strong amateur about playing on the top at h17 (I think rggers mentioned only k17 and j17 so it is worth considering why the extra stretch), Kudo dismissed it out of hand as "no good" because it lets White play q15, r15, q14, r14, r16 (see diagram).

I will post the third instalment tomorrow (Wednesday) evening GMT as I think some more discussion of this position _strategically_ would be useful for many players. It does, in fact, define the shape of the rest of the game. You might like to try mapping out where you think the final territories will lie.

The concept of letting a moyo invader live small comes from a Takemiya book, by the way.

Definitions

(from Japanese books)

Tewari
Assessing the merits and demerits of joseki variations, or local positions that arise in games, by analysing the efficiency and effect of the stones. This may involve making comparisons with josekis of similar shapes or adding or removing several stones to see the core position.

-- John Fairbairn