me vs a KGS 2d, or "how to get into trouble while reducing"

flOvermind · Post by **flOvermind** » Tue Nov 02, 2010 4:55 pm

This is a game with me playing black against a KGS 2d.

The fuseki was very strange. My opponent played a few moves that I would critisize in the game of a weaker player, but he is quite a bit stronger than me (don't be fooled by my 1d rating, that's based on only 7 games

).
After fuseki I felt ahead. Then I seriously screwed up a reduction, and the game went downhill from there...

I placed a few comments and questions directly in the SGF.

To sum up: I know where I screwed up, but I have no idea what I could have done to prevent it.

sekoj · Post by **sekoj** » Tue Nov 02, 2010 6:06 pm

Brief look while wait for my mug of hot cocoa, come on stove

15: if at p6 then white just takes the 4th line jump? I tend to like points as white.
19: wrong block. r4->n3->p2->m6 .. or tenuki at p2
after 20 with q3 block, r4 feels horribly needed for me . peep at p2 / block at r4 can be painful later
23: Instantly looking at attach to 22 at h4, make white over-concentrated
24: ;oo unexpected side other side joseki and then white can maybe do the crude E7, then lean on the other side at q7 .. nice moyo? nevermind white
33: at f10 and no problems?
37: connect at g9 and give him a couple of stones if he really really wants them. After cut just feels too painful black

Numsgil · Post by **Numsgil** » Tue Nov 02, 2010 10:39 pm

Re: The reduction.

There's a 'rule' that says that when you are contacted by a stone you must gain liberties for that stone until it's stable. The diagonal white shoulder hit is a contact play. Any attachment to white's stone would also be a contact play. Anyway, white extends to gain liberties, and to build a wall that he hopes will provide profit (by attacking your corner maybe?). You must then extend to gain liberties yourself (also needs to remove a white liberty or be diagonal to a white stone). You can't hane or jump yet because locally white is much stronger.

After extending once white and black both have 5 liberties. Which is the minimum number of liberties that are stable. White could take sente and move somewhere instead of gaining liberties. But he decides to push from behind once more so you don't have sente contact moves against his wall. When he extends, he reduces your liberties to 4. You must extend once more to gain liberties to at least 5 (ideally no more than 6). When you jumped instead, that was a mistake.

White won't keep pushing you from behind. Why? Because if he does, it's gote. You don't need to respond in contact. You can jump and make shape, or play in another part of the board or whatever (actually, you should jump or build a base on the side, depending on if you want to live or run). If he wants to keep running he'll make a knight's move himself. But then he has to fall back a bit and you get some breathing room to do whatever.

...

When white wedged into the cut that was white going 'OMG roxxor Black fubar, I cut now'. If you've ever watched Day 9 Starcraft 2 videos, when a player goes for a crazy all-in attack after an opponent makes a mistake, he calls that 'getting a boner'. IMO white got a boner when he saw you screw up and wanted to capitalize on it immediately. (It maybe actually be the best refutation, but it seems pretty all-in to me).

Anyway, once you know that rule, it makes a lot of play like this make way more sense. Pros almost always follow this rule, as do joseki. (Contact Fights talks about this in great depth (I don't mean to keep spamming Wilcox's stuff, but it does a pretty good job of explaining this stuff and it seems to come up a lot)). The exceptions involve high level reading that always gets me in to trouble.

Afterwords, after extending, white should get sente (starting contact is usually gote) and will try to attack you by enclosing you inside his moyo or at least escaping with his stones (the reason A&D says white will slide). You try to build a base and live locally -or- run away to friendly stones and counter attack white. Reductions usually try to run.

I won't comment on anything else in the game to avoid making a fool of myself

But about this specific reduction, in total isolation on the board, I feel pretty confident I know what I'm talking about.

Bill Spight · Post by **Bill Spight** » Tue Nov 02, 2010 11:11 pm

A few comments:

flOvermind · Post by **flOvermind** » Wed Nov 03, 2010 2:41 pm

Thanks for all the comments. Especially to Bill for the detailed review, there are several comments in there that seem really obvious in hindsight, but would never have crossed my mind in the game

And I think I really need to get hold of Contact Fights

. I have never heard of the heuristic about keeping 5 liberties in pushing battles, but now that you mention it it seems really logical to just extend once more, and then jump, make a base or whatever.

mitsun · Post by **mitsun** » Wed Nov 03, 2010 6:44 pm

Here is a quiz, based on the previous discussion. B has just played the marked move, and W wants to escape lightly with the marked stone. Find the next sequence of moves for both players. (The game is Fujisawa Hideyuki (B) versus Rin Kaiho (W) from a Meijin match in 1970.)

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

flOvermind · Post by **flOvermind** » Thu Nov 04, 2010 2:48 am

That's an interesting example, because I would have assessed the position completely differently.

Yes, the white stone is under attack and needs to escape, but I would have tried to do that in a way so I can turn around the attack and pressure the single black stone on the top side. That's pretty much the opposite of the "correct" strategy. I feel like I just got quite a bit stronger just by looking at this example

hyperpape · Post by **hyperpape** » Thu Nov 04, 2010 7:21 am

Bill, I notice that you mentioned Wilcox's rule of 5. This may be the first time I've heard a strong player mention any of his rules while giving advice. Would you mind saying something about how you see Wilcox's ideas? That is, how helpful do you think they are (and for whom?), what role do they play in thinking through a position, or whatever else strikes your fancy.

This is really just for the sake of my curiousity.

Life In 19x19

me vs a KGS 2d, or "how to get into trouble while reducing"

me vs a KGS 2d, or "how to get into trouble while reducing"

Re: me vs a KGS 2d, or "how to get into trouble while reduci

Re: me vs a KGS 2d, or "how to get into trouble while reduci

Re: me vs a KGS 2d, or "how to get into trouble while reduci

Re: me vs a KGS 2d, or "how to get into trouble while reduci

Re: me vs a KGS 2d, or "how to get into trouble while reduci

Re: me vs a KGS 2d, or "how to get into trouble while reduci

Re: me vs a KGS 2d, or "how to get into trouble while reduci