I learned go from my dad when I was a teenager. I never participated any ranking system. My dad was amateur 3 dan in China and at the end of my high school my win rate against him was near 100% with black and ~70% with white. I haven't played a single game since college. Recently I met a friend who also plays go (first one in 18 years ) and I'm trying to getting back into the game now.

I posted the game yesterday in KGS sub-forum because of some bad manner move at the end of game. This post here is mostly for me to review the game and learn my mistakes.
This was my second ranked game on KGS. The first one I won against a 6-7k robot and I was ranked '6k?' after that. I was auto-matched against my 4k opponent in this game and was given 2-stone handicap.


interesting move, only happens in handicap games I think;
again strange move, normally people challenges from corner;
my opponent likes to fight;
after , is at a very bad position, but white needs to deal with the weakness around K5. , are very slow and make the whole group heavy, in exchange and defends both corners and still keeps white group afloat. At this point I realized my opponent was indeed weaker than me and I had a game plan centered around punishing the white group around K5.
in joseki black can S18 to defend the corner or R15 to give up the corner and build a wall around top-right corner. In either cases at O10 became a good move. So I played at R15 and to connect it back. After , white gained more locally because white got the corner and are on Q lines not R lines, but because at O10 loses efficiency and make P12 point less important. Black still has influences towards center (still aiming for K5 white group) and can now move to top-left. and are situational moves to trying to follow my game plan, they are bad exchanges in top-right area.
I expected this move from white, but was bad move, either J16 or L16 would be much better. After , and are in danger. , big mistake from white, need to cut off black at H18 now. Again and makes white heavy and loses initiative in the center.
relief from white mistakes, keep moving towards center.
to , connects white group to top-left, this is still a mistake, again white needs to jump into the center, after and the white top center group is not an easy kill, there's always to sequence to connect back to corner later. White is trying to cut off the two black stones near top-left, but those two stones are very light. All white did from this connection move was small yose.
key, this is what white should have done back when handling the bottom center groups. Now white don't even have a good point to attack black in top-left area. White should invade left now.
white had to invade left after , is still aiming for the bottom white group, this allows to connect but I was stubborn and wanted to stick to my game plan.
biggest mistake in this game, C10 then A15 and black would kill white (A18 sente), should still play A15. This is what you get by playing a game and watching youtube at the same time. White now kills black instead. This was almost a 40-point loss and I had to count territory first time in this game. I found black was still winning by ~20 points if black take H11 position. The fight in center will now decide the game (ironically it was also my game plan).
White again missed and let :b116: into the center first. After :w133:, there is now a black wall in the middle and white got 10-15 points worth of territory from the thick white wall on top. White loss is now almost inevitable.
:b134: was a mis-click, I meant to play K7. This would be a complicated fight in center but I don't know what would be the outcome of this fight, but black is very ahead and have few worries after settling the weakness in center.
The actual fight till :b140: resulted in white easily alive. I was disappointed at :b134: mis-click but black is now >35 points ahead.
:b142: another mistake, should play at D6, because of the weakness around G9. After :w147:, I needed to be careful with yose afterwards, it's only 20 point lead now.
:w153: big mistake from white, need to make G8 move to connect (white F8 sente). After :b160: white not only died bigger near bottom left but also built now black wall very close to bottom center white group. Black is now again 40+ points ahead, I've won no matter what but I'm not done yet with the white K5 group. The group is now almost alive, but if black has 1 sente to cut it off from right...
:b168: big yose and I was still looking for that sente. Unnecessary fight from :w169: gave black the sente needed. :b172: I would normally play at R8 and then Q8, white would lose more territory because of weakness around R14. The actual fight gave black the sente needed :b180: P7, but I probably should have played M3 before.
:b188: last serious mistake from black. :w189: is sente, but both black and white missed this. I realized this soon and connected back with :b208:. After that there weren't many big yose left.

White missed last chance at :w153:, I knew I won after that. The moves to kill white K5 group was just toying with my opponent.

This game was unfair to my opponent to start with. I won because I read my opponent very early in the game and stuck to my game plan the whole game, he likes to fight and he lost the game by doing unnecessary fights.

I made so many mistakes in the game, the 40-point mistake at would be game deciding against a stronger opponent. Need a lot more practice and focus on the game.

Just one comment: 18 should cut, because 19 is a wonderful thick move.

If black cut nows, white could just give up 2 stones and build a thick wall on top, (White 3 is already at high position and black still need to defend bottom left corner), black does not gain much because black is very thick in the bottom. Defend both corners are way more important, not just territory-wise but also limit the potential of "thick" white bottom group. Thick with no potential is just slow.

Do you really think this is smaller than r6?

Click Here To Show Diagram Code

[go]$$Bc
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . 6 . . . . . . . . . |
$$ | . . . . . . . 4 2 X . . . . . . . . . |
$$ | . . . . . . 5 3 1 O O . . . . . . . . |
$$ | . . 7 X . . . O O X O O . . . X . . . |
$$ | . . . . . . . . X X X . . X . . . . . |
$$ | . . . . . . . . . X . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ +---------------------------------------+[/go]

The 2 stones are quite big and thick, for example now if white n3 black can answer at o4 if he wants to reduce the centre and allow white to split at n2 as a big gote endgame move which no longer threatens the 5 stones to the left.

This makes white next move at Q6 wonderful.

But wasn't c4 also wonderful? I don't mind if white makes some points/potential if black makes more. Perhaps this next? I feel black has maintained his 2 stone advantage if not extended it here. Should white have approached at r14 before q6? The aji of k6 could come in handy in a reduction of white's centre right area (for example o8 might become an interesting move).

Click Here To Show Diagram Code

[go]$$Bc
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . 9 . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . 6 . . . . . . . . . |
$$ | . . . . . . . 4 2 X . . . . . 8 . . . |
$$ | . . . . . . 5 3 1 O O . . . . . . . . |
$$ | . . 7 X . . . O O X O O . . . X . . . |
$$ | . . . . . . . . X X X . . X . . . . . |
$$ | . . . . . . . . . X . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ +---------------------------------------+[/go]

You are right that white will approach R14 then Q6. This will make white initial moves around K5 to be efficient. With black defending the bottom corners first, there is no good position for white to make K5 group efficient. This extends black's advantage by another stone probably. The aji of K6 is certainly useful if black decides to reduce white area at center. But why should I let white build up an area in the center first?

Because you built a huge lower left in exchange (though maybe you are right it's not such an interesting area). Also in the game white still has some centre potential (e.g. q7). Or if you insist on killing r3 invasion maybe white can find a way to sacrifice it for some outside stones.

If c6 makes you so sad you don't need to defend the lower left 3-3 with my move 7 but could play around there.

Btw, as a more pragmatic argument for the cut, I doubt many KGS 4ks would sacrifice the 2 stones but try to save them and make a heavy group for you to attack

C4 isn't necessary and Black has a perfect ladder breaker at P9 in this diagram. Somewhat on a tangent, I think you're really underestimating the importance of thickness.

Q7 after R6 is much less efficient because the right side is basically open to black with R6 already at low position. Comparing to white Q8 and no black stones on R line, white will be buliding up both right side and center.

Shaddy, it's a net not a ladder, though if you use the net the g6 turn threatens to escape if white doesn't have the north-west ladder. White can g6 push in sente, but I'm not sure that's a good exchange before black defends the lower left as if you do it before maybe black can try to kill the 3-3?

ystao, sure white's centre/right is much better if he plays there first, but black's lower left is much better with the cut. I'm not saying cut is the only move, both ways seem playable to me; I wonder what other dan players here think.

Ah, you're right. In that case I like q13 instead of c4.

Black defending both corners are thick and with potential towards left and right sides. White K5 group with no good position to develop is just slow. In this game I almost gave white every fight and was still easily ahead because white only used the thickness to very low efficiency. I certainly did not underestimate thickness in this game.

For example, black jumps into center at L12, this is respecting the thickness of white around, any closer to white wall would be inviting a bad fight.

Click Here To Show Diagram Code

[go]$$Bc
$$ + ---------------------------------------+
$$ | . . . . . X . . . . . . . . . . . . . |
$$ | . O . O X . X X X O X X 3 . . . X O . |
$$ | . X O O O X O O O X X O 2 X 1 . X O . |
$$ | . X . O O O O . . O O . O O . X O O . |
$$ | O X X X O X . . O X . . . . 6 X X O . |
$$ | O X X O X X . . . . . . . 5 4 X O . . |
$$ | O O X O O X . X . . . . . . X O . . . |
$$ | . O X O X O . . . . 7 . . . . O . . . |
$$ | X O O O X O . X . . . . . . . . . . . |
$$ | . X . X X O . . . , . . . . . O . . . |
$$ | . X . . X . . X . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . O X . . . . . . X . . |
$$ | . . . . . . . . . O O . . . . . . . . |
$$ | . . . X . . . O O X O O . O . X . . . |
$$ | . . . . . . . . X X X . O X X . . . . |
$$ | . . . . . . . . . X . . X . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------+[/go]

Black only now makes move towards K6 after black is thick in the center is also respecting the thickness of white.

Click Here To Show Diagram Code

[go]$$Bc
$$ ---------------------------------------
$$ | . . . . . X . . . . . . . . . . . . . |
$$ | . O . O X . X X X O X X X . . . X O . |
$$ | . X O O O X O O O X X O O X X X X O . |
$$ | . X . O O O O . . O O . O O O X O O . |
$$ | O X X X O X . . O . O . . . O X X O . |
$$ | O X X O X X . O O O X X . X O X O . . |
$$ | O O X O O X X X O X . . . O X O . . . |
$$ | . O X O X O . . X . X O O . . O . . . |
$$ | X O O O X O . X . . . X X . . . . . . |
$$ | . X . X X O . . . , . . . . . O . . . |
$$ | . X . . X . . X . . . . . . . . . . . |
$$ | . . . . . . . . . 1 . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . O X . . . . . . X . . |
$$ | . . . . . . . . . O O . . . . . . . . |
$$ | . . . X . . . O O X O O . O . X . . . |
$$ | . . . . . . . . X X X . O X X . . . . |
$$ | . . . . . . . . . X . . X . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Thickness is locally slow and inefficient, it only repays you if you can develop an area on it or force your opponent's weak group run towards it. I was avoiding both in this game and leaving white with only slow and inefficient.

If you have to respect the thickness, it's already working. That's why it's useful; whoever is thicker has more freedom over the whole board. I agree, you outplayed your opponent and made his thickness useless; I think you're stronger than him. But I still think White's result at 19 is quite nice.

I never said thickness is "useless", any stone on board can be useful, the question here is efficiency and follow-up moves. Thickness is an investment for future. In this case, white has no good position for next move in bottom half. White is forced to play in top-half and black has no immediate worries in bottom half either (ie. black is also thick in bottom half). But black has ~30 points territories in bottom half at this moment, white has no good options to build up 30 points territories using its thickness. At this point, white is struggling to find next move.

Click Here To Show Diagram Code

[go]$$Wc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . O X . . . . . . X . . |
$$ | . . . . . . . . . O O . . . . . . . . |
$$ | . . . X . . . O O X O O . . . X . . . |
$$ | . . . . . . . . X X X . . X . . . . . |
$$ | . . . . . . . . . X . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

If black cuts off white:

Click Here To Show Diagram Code

[go]$$Bc
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . 6 . . . . . . . . . |
$$ | . . . a . . . 4 2 X . . . . . b . . . |
$$ | . . . . . . 5 3 1 O O . . . . . . . . |
$$ | . . . X . . . O O X O O . . . X . . . |
$$ | . . . . . . . . X X X . . X . . . . . |
$$ | . . . . . . . . . X . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ +---------------------------------------+[/go]

In this situation it's clear a or b would be wonderful next moves. Cutting off white with is helping white to find next move. I agree that the black is also in big lead, but white's game plan is also clear at this point.

Ahh, I get it now. That's an idea I haven't thought about much, and I agree now. Thanks for being patient with me.

Those 2 diagrams are a bit misleading though because in the first it is white sente and in the second black has sente. So how about comparing these?

Click Here To Show Diagram Code

[go]$$Wc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . O X . . . . . . X . . |
$$ | . . . . . . . . . O O . . . . . . . . |
$$ | . . . X . . . O O X O O . . . X . . . |
$$ | . . . . . . . . X X X . . X . . . . . |
$$ | . . . . . . . . . X . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Click Here To Show Diagram Code

[go]$$Bc
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . O . . . . . . . . . |
$$ | . . . a . . . O O X . . . . . . X . . |
$$ | . . . . . . X X X O O . . . . . . . . |
$$ | . . . X . . . O O X O O . . . X . . . |
$$ | . . . . . . . . X X X . . X . . . . . |
$$ | . . . . . . . . . X . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ +---------------------------------------+[/go]

What next for white do you fear in the 2nd? This? Next a for black? k6 is more interesting later now that black got the turn which makes up for the slightly slow feeling I get.

Click Here To Show Diagram Code

[go]$$Wc
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . a . . . . . . . . . . . . . |
$$ | . . . O . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 7 , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . O . . . . . . . . . |
$$ | . . . 1 . . 2 O O X . . . . . . X . . |
$$ | . . 5 . . . X X X O O . . . . . . . . |
$$ | . . 3 X . . . O O X O O . . . X . . . |
$$ | . 6 4 . . . . . X X X . . X . . . . . |
$$ | . . . . . . . . . X . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ +---------------------------------------+[/go]

Interesting position

In this case white has a good configuration on the left side. is already in a low efficiency position. Black is not thick in bottom left after so many stones invested, this is troublesome. For example, black bottom left does still F4 weakness, with a little prep(white can't do this right now) white could use this to move out the two white stone and the four black stone would be cut off and fight next to the thick white group.
Also can simply go to bottom-left 3-3, if black covers from bottom then it's very low efficiency in bottom for black. If black covers from left-side because of the high position of and thickness of white center group, it's hard to build up an area efficiently on the left.
Or white could G6 before D6 try to shut black in completely and aim to build a huge area with a stone around K12. Lots of good options for white.
In any case, fighting on bottom half of the board is going to make white thick center group efficient. It's best option to avoid any fight near that group and reduce its potential from afar.
Edit: Actually black is already in very awkward position when goes to C3 directly.

I asked Jeff Chang 6d about this position. He said tenuki was a no-no, cut was a compromise, but acceptable for cashing in a lot of territory but does make it easier for white too, but he prefers to attack the group as a whole:

Click Here To Show Diagram Code

[go]$$Bc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . 5 3 . . . . . . . . . . |
$$ | . . . . . . . 1 2 X . . . . . . . . . |
$$ | . . . . . . . . 4 O O . . . . . . . . |
$$ | . . . X . . . O O X O O . . . X . . . |
$$ | . . . . . . . . X X X . . X . . . . . |
$$ | . . . . . . . . . X . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Attack whole group is certainly better than cutting directly . But white wouldn't just connect 2 stones and be heavier. No doubt white will fight back with and then jump into center with (white should just into the center instead of J6 anyway), black 3 stones are bit heavy now. White 2 stones are light because of bottom-left 3-3 if black still wants to cut (and white G5 counter-attack is possible if white is settled in the center). If black keeps fighting in the center there probably will be a white wall in center-right side and white Q10 is now a good move(and build up an area in center-right of the board). And black is also risking white connecting those 2 stones back and attacking black in center if white easily settles in center. All these are still better than cutting directly but I still consider these to be helping white to play. White should welcome a fight in the center because black is moving against more white stones in the center and away from most black stones.

Click Here To Show Diagram Code

[go]$$Bc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . 2 . .4 . . . . . . . |
$$ | . . . . . . . 1 3 X . . . . . . . . . |
$$ | . . . . . . . . . O O . . . . . . . . |
$$ | . . . X . . . O O X O O . . . X . . . |
$$ | . . . . . . . . X X X . . X . . . . . |
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$$ ---------------------------------------[/go]

Also blacking defending bottom corners is not simple tenuki, it's a method to reducing white center group's influence and a very much correlated move in the bottom half of the board. A tenuki would be a move in the top half of the board.