Please analyze my analysis of 9x9 game with dan-level player

[HokieGeek]

Played this 9x9 game with Janssensei on DGS who is rated 3d against 9x9 boards on DGS. I've commented the SGF with my own analysis of how I played (very, very badly) and was curious of any of you could help me see if I my analysis makes sense and if I missed anything. Thank you in advance!



As a bit of a shortcut, I commented on the following moves:

[Charles Matthews]

Played this 9x9 game with Janssensei on DGS who is rated 3d against 9x9 boards on DGS. I've commented the SGF with my own analysis of how I played (very, very badly) and was curious of any of you could help me see if I my analysis makes sense and if I missed anything. Thank you in advance!



As a bit of a shortcut, I commented on the following moves:

Standard algebraic notation: letters on the x-axis, numbers on the y-axis.

Your aim should be to take more than 50% of the board. So playing D5 is a more natural plan.

It is natural just to play C2 here. D2 can be considered an "overplay".

If you connect at B8 the group is alive. See http://senseis.xmp.net/?FiveStonesOnThe ... nTheCorner for the minimum you need (second line territory, when including a corner).

You are right: there is a ko here. Black B9, White C9 is ko. Black plays D4, which is a good threat, White plays E3. Black takes back at C8. White A8 is a local ko threat (no good for Black to connect). So Black at A7, White takes at C9, Black B2, White E9 finishes the ko. At this point Black is alive on the left. Shapes for that are at http://senseis.xmp.net/?SixDieButEightLive. So it would make sense for Black to play F4. Which would allow Black life on the right, I believe.

It would have been simpler to play B8!

must be B2: basic life-and-death on the second line.

After , White will win.

[HokieGeek]

Your aim should be to take more than 50% of the board. So playing D5 is a more natural plan.

Oh that does look better than going on the star point. I guess my thought there was to have to force white to escape, but I do like this more.

It is natural just to play C2 here. D2 can be considered an "overplay".

Ah! Ok, fair enough. I see how that constricts white more than either what I played or what I thought I should have played.

If you connect at B8 the group is alive. See http://senseis.xmp.net/?FiveStonesOnThe ... nTheCorner for the minimum you need (second line territory, when including a corner).

Yeah, that makes WAY more sense than what I did. But, then, most other moves would have. Tenuki is always an option. Need to learn not to panic x-D!

You are right: there is a ko here. Black B9, White C9 is ko. Black plays D4, which is a good threat, White plays E3. Black takes back at C8. White A8 is a local ko threat (no good for Black to connect). So Black at A7, White takes at C9, Black B2, White E9 finishes the ko. At this point Black is alive on the left. Shapes for that are at http://senseis.xmp.net/?SixDieButEightLive. So it would make sense for Black to play F4. Which would allow Black life on the right, I believe.

It would have been simpler to play B8!

That ko is painfully obvious now. I'm still reading up on the basic shapes. I shall continue reading!

must be B2: basic life-and-death on the second line.

isn't white at B2 at this point with ? What am I missing?

After , White will win.

Oh boy. I didn't realize I had lost the game this early on. I thought I had lost it closer to the 30s as white kept killing my points. But, I can see now that having lost so many stones and territory on the left, it would be impossible for me to catch up in territory.

Many thanks! This really helps

[EdLee]

must be B2: basic life-and-death on the second line.

isn't white at B2 at this point with ? What am I missing?

( Not sure what you're asking in the first part of your question. )
If at B2, your B3 group can live; after White gets B2, your group dies.

The game move, at D6, is not OK, not good.

[HokieGeek]

must be B2: basic life-and-death on the second line.

isn't white at B2 at this point with ? What am I missing?

( Not sure what you're asking in the first part of your question. )
If at B2, your B3 group can live; after White gets B2, your group dies.

The game move, at D6, is not OK, not good.

OHHHHHHHHHH! Ok, ok. I completely messed up the coordinate system and thought A1 was top-left corner :facepalm:. That really changes what I got from Charles' comments!

Ok, cool. That now makes sense. So I had a chance of saving my group and lost it with . Not good is correct. Thanks!

[EdLee]

I completely messed up the coordinate system and thought A1 was top-left corner

The forum software displays the coordinates by default for 19x19.
If you ask politely, maybe someone here will improve it for smaller boards, too.