Life In 19x19

To John: although I am not a visual person, I have "visuals" for invasion/reduction rather than synonyms or any kind of taxonomy.

What I see is:

| \ O / |
| x-terr |

| / X \ |
| O-life|

A convex end result of a reduction, a concave one for an invasion.

As mentioned before, what I think is wrong about that is that I don't usually take into account the effect of an invasion on the surrounding structure.

So, whether verbally or visually, I think we need words or images that stimulate invasions in case of corrosive structure and encourage reductions in the solid case.

Bill Spight wrote:Here is a game by Kitani well after his prime, where he beat one of the young stars of the day...

Just out of curiosity, what do you consider Kitani's prime? He was ranked number 5 in mamumamu's historical list for July 1964, which is where this game enters his data. He was behind only Sakata, Go, Fujisawa Hosai, and Takagawa. Hashimoto was ranked 12th in that list.

ez4u wrote:

Bill Spight wrote:Here is a game by Kitani well after his prime, where he beat one of the young stars of the day...

Just out of curiosity, what do you consider Kitani's prime? He was ranked number 5 in mamumamu's historical list for July 1964, which is where this game enters his data. He was behind only Sakata, Go, Fujisawa Hosai, and Takagawa. Hashimoto was ranked 12th in that list.

I suppose that Kitani's prime came by 1954, when he fell ill.

In terms of title wins and appearances in title matches, Kitani's prime was clearly 1956-1961. He reached 9-dan in 1956.

In terms of when a significant number of people in Japan thought he might be No. 1. it would be around 1938, which perhaps matches his age prime best: he was born in 1909.

As regards illness, the first significant affect on his career was 1954 when he stopped playing in the Oteai, though it had appeared well before then. It ended his career (and school) only in 1974. He died in 1975.

FWIW, my definitions of invasion and reduction are:

An invasion is a stone which is placed in an area which is almost surrounded by enemy stones, which aims
(1) either at living locally (i.e. living while being surrounded)
(2) or at escaping while splitting the opponent into two groups.

The invader may sometimes change his mind, invading stones may be sacrificed in order to get a strong outside influence.

A reduction is a stone placed close to or inside the enemy's sphere of influence, which achieves neither (1) nor (2), and which must escape to the center in order to survive.

rhwocns wrote:SGF with variations

Much appreciated, thank you.