Countermeasures to invasions - defending by numbers

John Fairbairn · #1

We've had some fun with numbers in recent posts. Here is an example from Japan where numbers are used to mark the degree of risk associated with 39 common formations.

The book is アマの知らない打ち込み対策事典 or "Catalogue of countermeasures to invasions that amateurs don't know". It is by Awaji Shuzo 9-dan (ISBN 978-4-8399-2610-6, Mainichi Communications, 2007; 223 pages, about 1400 yen).

For each position, Awaji gives a percentage, which is meant as a guide to the likelihood of the territory or base of that position being disrupted in actual play. The figure is supported by a brief supporting comment (e.g. "Don't think of this shape as territory" or "This territory is worth about 10 points"). The numbers, of course, are largely decorative, but seem to be in the right ballpark. I did a small survey with the GoGoD database. This confirmed that the positions were indeed common (typically of the order of 100 games upwards) and that the percentages were reliable enough. E.g. for a position marked 60% risk, I looked at 10 games. In 5 the position was indeed later disrupted, in 4 it wasn't, and 1 case was borderline.

The real meat of this book, however, is in the explanations of the weak points of each position. In each case, a Black position is invaded by White, and the book shows various results, ranging from the typical duffer's response to Awaji's recommended response. Sometimes the recommended response kills the invader, sometimes it just minimises damage. In some cases there is more than one recommended line. For some positions Awaji also shows best next move for Black - the mamori (pre-emptive defence) move.

Only the corner positions are shown - there are no game or full-board examples - but this part is excellent, ausgezeichnet, A1, whizzo, just dandy, the bee's knees, well worth a shufty, on the money, spiffing, not bad at all, cushty. You might even end up saying, "Cor, love a duck!"

Below I give a selection of positions from the book, where you may wish to make your own assessment of the risk factor in each case, assuming White plays next (0% means it's totally safe; units of 10% only). A low figure means you see little risk that Black loses his base or the bulk of his territory and that White gets away scot free. Obviously (I hope), this also assumes that White's various possible invasions are well timed in terms of the rest of the board. The White positions here are partly just indicative of outside strength. Awaji's figures are given at the end, but I won't hide the answers or delay them. Instead, I'll bury them in a solid paragraph and trust you to keep your eyes on the road.

The test here is not meant to be taken too seriously - it's just a coffee-break moment. The real point of the examples is to give a notion of the sort of positions covered by the book.

Click Here To Show Diagram Code: [go]$$ Diagram 1 $$ ------------------------- $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . O . . O . X . . . . . | $$ . . , . . . . . X X . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . O . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . O . . | $$ . . , . . . . . , . . . | $$ . . . . . . . . . . . . |[/go]

Click Here To Show Diagram Code: [go]$$ Diagram 2 $$ ------------------------- $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ O . . O . X . . . . . . | $$ . . , . . . . . X X . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . O . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . O . . | $$ . . , . . . . . , . . . | $$ . . . . . . . . . . . . |[/go]

Click Here To Show Diagram Code: [go]$$ Diagram 3 $$ ------------------------- $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ O . . O . X . . . . . . | $$ . . , . . . . . X . . . | $$ . . . . . . . . . X . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . O . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . . , . . . . . , O . . | $$ . . . . . . . . . . . . |[/go]

Click Here To Show Diagram Code: [go]$$ Diagram 4 $$ ------------------------- $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . . X . . . . . . . . . | $$ . . , . . . . . X . . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . X . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . . , . . . . . , . . . | $$ . . . . . . . . . . . . |[/go]

Click Here To Show Diagram Code: [go]$$ Diagram 5 $$ ------------------------- $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . . X . . . . . . . . . | $$ . . , . . . . . X . . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . X . . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . . , . . . . . , . . . | $$ . . . . . . . . . . . . |[/go]

Click Here To Show Diagram Code: [go]$$ Diagram 6 $$ ------------------------- $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . . X . . . . . . . . . | $$ . . , . . . . . X . . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . X . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . . , . . . . . , . . . | $$ . . . . . . . . . . . . |[/go]

Click Here To Show Diagram Code: [go]$$ Diagram 7 $$ ------------------------- $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . . . . O . X . . X O . | $$ . . , . . . . . X . O . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . O . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . . , . . . . . O . . . | $$ . . . . . . . . . . . . |[/go]

Click Here To Show Diagram Code: [go]$$ Diagram 8 $$ ------------------------- $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . . . . . . . X . . . . | $$ . . , . . . . . , X . . | $$ . . . . . . . O . . . . | $$ . . . . . . . . . O . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . O . . | $$ . . , . . . . . , . . . | $$ . . . . . . . . . . . . |[/go]

Click Here To Show Diagram Code: [go]$$ Diagram 9 $$ ------------------------- $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . . O . . O . X . . . . | $$ . . , . . . . . , X . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . O . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . O . . | $$ . . , . . . . . , . . . | $$ . . . . . . . . . . . . |[/go]

Click Here To Show Diagram Code: [go]$$ Diagram 10 $$ ------------------------- $$ . . . . . . . . . . . . | $$ . . . . . . . X O O . . | $$ . . O . X . O X X O . . | $$ . . , . . . . . X O . . | $$ . . . . . . . . X . . . | $$ . . . . . . . . . O . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . . , . . . . . , . . . | $$ . . . . . . . . . . . . |[/go]

Click Here To Show Diagram Code: [go]$$ Diagram 11 $$ ------------------------- $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ O . X . . . X O O . . . | $$ . . , . . . X X , O . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . O . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . . , . . . . . , . . . | $$ . . . . . . . . . . . . |[/go]

Click Here To Show Diagram Code: [go]$$ Diagram 12 $$ ------------------------- $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . O . X . . . . X X O . | $$ . . , . . . . X , O . . | $$ . . . . . . . . . . O . | $$ . . . . . . . . O . . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . . , . . . . . , . . . | $$ . . . . . . . . . . . . |[/go]

Click Here To Show Diagram Code: [go]$$ Diagram 13 $$ ------------------------- $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . . O . X . . . X X O . | $$ . . , . . . . X , O . . | $$ . . . . . . . . . . O . | $$ . . . . . . . . O . . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . . , . . . . . , . . . | $$ . . . . . . . . . . . . |[/go]

Click Here To Show Diagram Code: [go]$$ Diagram 14 $$ ------------------------- $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ O . . O . X . . X . . . | $$ . . , . . . . . , . . . | $$ . . . . . . . . . X . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . O . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . . , . . . . . , O . . | $$ . . . . . . . . . . . . |[/go]

Click Here To Show Diagram Code: [go]$$ Diagram 15 $$ ------------------------- $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . X . O . . O X . . . . | $$ . . , . . . O . X . . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . X . . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . . , . . . . . , X . . | $$ . . . . . . . . . . . . |[/go]

Click Here To Show Diagram Code: [go]$$ Diagram 16 $$ ------------------------- $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . X . O . . O X . . . . | $$ . . , . . . O . X . . . | $$ . X . . . . . . . . . . | $$ . . . . . . . . X . . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . . . . . . . . . . . . | $$ . . , . . . . . , X . . | $$ . . . . . . . . . . . . |[/go]

Awaji's risk factors are as follows: 1 = 0%, 2 = 60%, 3 = 40%, 4 = 20%, 5 = 30%, 6 = 40%, 7 = 50%, 8 = 20%, 9 = 60%, 10 = 60%, 11 = 40%, 12 = 50%, 13 = 5% (yes, I lied about 10% units, but this is the only exception), 14 = 10%, 15 = 30%, 16 = 10%.

Your eyes may pop at some of the figures, not just in absolute terms but relative to each other. The book's text may still not convince you but will teach you a lot. One especially useful side benefit is that when you compare one position against another that differs by just one stone, you get a surprisingly new insight into the effect of that extra stone.

Do you need to read Japanese to get value from this book? No. Perhaps the only two phrases you really need are オススメ！(Recommended) and 守り方 (How to defend pre-emptively). These appear as luggage labels under the relevant diagrams.

Chew Terr · #2

Wow, this book seems really intriguing. While I'm hesitant to order it currently (I have too many books to work through already and I'm lazy so I don't import things too often), this description is really interesting and puts it first on my list of things I want to import, the next time I work up the gumption to. Thanks as always John, for the quality information and presentation. Heh, 'well worth a shufty' is a new one on me.

snorri · #3

I'm not sure I understand what the risk numbers really mean. If you just look at diagrams 4-6, white can invade in a few places with no problems. There are even standard patterns in books for those positions. Are we just asking how common it is for white to get to play first in those positions before black defends? On some internet Go servers, if you build one of those positions in 4-6, it will be invaded almost 100%, so Awaji's much lower numbers mostly just show how much less greedy professionals are than amateurs.

(BTW, it's interesting to see his opinion on the risk difference between 15 and 16.)

hyperpape · #4

John Fairbairn wrote:

A low figure means you see little risk that Black loses his base or the bulk of his territory and that White gets away scot free.

Doesn't that answer your question, snorri? It's not whether there are invasion points, it's a matter of what the invasion points leave the board looking like--is White safe? Does Black have territory?

topazg · #5

Ok, mod step-in time. I have removed all references to wives and marriages, and taken this meta discussion elsewhere so John's thread stays in the context it was intended. Robert, please keep discussions about the wording used outside of this thread.

RobertJasiek · #6

John, for which reasons do you consider the corner part of the book excellent and what does it do better than other related books? Is the quality of other chapters significantly different?

rubin427 · #7

Any advice for how to order this book if I only speak english and am living in the USA?

I would really like to :study:

oren · #8

rubin427 wrote:

Any advice for how to order this book if I only speak english and am living in the USA?

I would really like to :study:

http://www.amazon.co.jp/%E3%82%A2%E3%83 ... 251&sr=8-1

You can order from here, but for one book shipping will be high.

If you're in a city with a Kinukinoya they can order it for you with ISBN.

http://bookweb.kinokuniya.co.jp/ohb/02/ ... einfo.html

RobertJasiek · #9

Amazon/Japan appears to have it:

http://www.amazon.co.jp/%E3%82%A2%E3%83 ... 164&sr=8-1

If this URL did not translate the Kanji correctly, simply go to

http://www.amazon.co.jp
and search for the ISBN
978-4839926106

Register with Amazon/Japan if you have not done it yet. Registering is easy enough if you are familiar with any other Amazon site. Press English where necessary. Enter International Address where necessary. Copy & Paste Japanese to

http://babelfish.yahoo.com/

where necessary. Shipping and import taxes can be expensive. Ordering from third sellers is possible; you just need to find out which offer International and national delivery.

Tami · **#10**

I have just finished reading this book for the first time. Here are my thoughts:

It's a technical book. That is, it shows you specific patterns and variations. It is about technique, rather than general principles. For that reason, it is not a fast and easy read. If you read it too quickly, you will just become confused. If you read it slowly, one section at a time, and with frequent reviews, then I am certain a lot of the information will stick and prove extremely useful.

For me, it's been very pleasant finding out how to deal with a number of situations I did not previously understand at all. Quite likely, I will still make more mistakes than correct moves in those situations, but now I know where to turn for guidance when reviewing a game.

It is not essential to understand Japanese to read this book, so long as you can distinguish between the markers for "recommended" and "defence", but if you do understand Japanese, it helps a lot because Awaji Shuzo sometimes states that an alternative to a "recommended" line may be a better choice, according to circumstances.

The danger numbers do not mean the likelihood of the opponent invading a given shape. They express the author's assessment of the risk of coming out with a bad result. If the figure is "10%" it means you have much less to worry about when playing tenuki than if the figure reads "70%".

At the most basic level possible, simply knowing the risk assessment for each shape should be very helpful, even if you don't bother studying the variations (which I think you should do, by the way!). That is, knowing if the shape is a 10% or a 50% or an 80% should help you when deciding whether to defend or tenuki, attack or simply observe. The more deeply you study the material, the better informed your judgements will become.

The book is comprehensive, and well supported by examples and discussion. Most commonly seen corner patterns are covered, and there are a number of side patterns too.

SUMMARY

This is a technical book covering frequently occurring corner and side patterns, providing an indication of the level of risk associated with each, and offering a range of counter-measures and pre-emptive defences. It would be possible to benefit from this book without knowing Japanese, but the Japanese commentary is certainly very helpful and revealing. It is not as entertaining as the books of Sonoda or Takemiya, nor as revelatory as Hane's book on honte, but it is well written and comprehensive. You can expect it to repay repeated review, and to prove useful in the long-term, as the patterns occur, and you increasingly find yourself able to gain good outcomes in them.

My rating: B+

PS: If you want this book or any other Japanese go manual, and cannot obtain it for a reasonable price on Amazon or elsewhere, send me a private message, and just possibly I could be persuaded to step over to the bookstore and export it to you. (The persuasion would take the form of purchase price, postage costs and a small consideration for the trouble.)

Countermeasures to invasions - defending by numbers

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