Atypical invasion

hyperpape · Post by **hyperpape** » Tue Aug 02, 2011 5:36 pm

I was looking at 501 opening problems for the first time in awhile, and I was surprised by the answer. I would have invaded low, having banished the high invasion from my mind after reading Attack and Defense. However, the invasion does seem to work well on this board.

Click Here To Show Diagram Code: [go]$$c The solution from the book. $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . O . . . . . . . X . . . . . | $$ | . . . O . . . . . , . . . . . , X . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . O 5 . . | $$ | . . . . . . . . . . . . . . . 4 3 . . | $$ | . . . . . . . . . . . . . . . 1 2 . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . . . O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . O , . X . . . , . . . . . , X . . | $$ | . . . . . . . . . X . . . . . X . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

What I'm wondering is the circumstances under which this invasion works, or anything else y'all know about it. I realize the two positions that follow are not very realistic games.

Click Here To Show Diagram Code: [go]$$c $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . O . . . . . . . X . . . . . | $$ | . . . O . . . . . , . . . . . , X . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . O 5 . . | $$ | . . . . . . . . . . . . . . . 4 3 . . | $$ | . . . . . . . . . . . . . . . 1 2 . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . . . O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . O , . X . . . , . . . . . , X . . | $$ | . . . . . . . . . X . . . . X . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Still feels ok with the shimari.

Click Here To Show Diagram Code: [go]$$c $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . O . . . . . . . X . . . . . | $$ | . . . O . . . . . , . . . . . , X . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . X . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . , . . . . . O 5 . . | $$ | . . . . . . . . . . . . . . . 4 3 . . | $$ | . . . . . . . . . . . . . . . 1 2 . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . O . . . . . . . . . . . . O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . O , . X . . . , . . . . . X . . . | $$ | . . . . . . . . . X . . . X . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

I have a gut feeling that the open corner makes this bad, but I feel like I might as well throw darts at the board as choose moves for either player.

Dusk Eagle · Post by **Dusk Eagle** » Tue Aug 02, 2011 5:56 pm

The first and final games you posted look realistic. The game with the corner shimari does make white's play a little odd though.

Anyway, I wish I could help, but I don't know much about this invasion. All I know is that this invasion occurred in the 66th Honinbo game 3 - I can't find this game right now, but perhaps with more digging you can find it.

Edit: Found it here:

hyperpape · Post by **hyperpape** » Tue Aug 02, 2011 6:47 pm

Funny, I watched that Honinbo game. I guess the invasion didn't register then.

The first game should look realistic. The authors took positions from actual games and from newspaper columns.

flOvermind · Post by **flOvermind** » Fri Aug 05, 2011 9:00 am

hyperpape wrote: I would have invaded low, having banished the high invasion from my mind after reading Attack and Defense.

You may be thinking about this position:

Click Here To Show Diagram Code: [go]$$ $$ . . . . . . . . $$ . . x B x O . . $$ . O . x . . . . $$ . . . . . . . . $$ . . . . . . . . $$ -------------[/go]

This is typically bad, you want to play at one of the 'x' points instead. That's because of the following variation:

Click Here To Show Diagram Code: [go]$$W $$ . . . . . . . . $$ . . 6 B 3 O . . $$ . O 4 1 2 . . a $$ . . 7 5 . . . . $$ . . . . . . . . $$ -------------[/go]

This result is considered good for white, because white gained a lot of territory for not much influence in return. Note the absence of a black stone at 'a'

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

But this situation is completely different, the additional black stone provides an easy escape route for

.
Also note that black is not the only one having a stone at the "bad shape" spot

.

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Atypical invasion

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