by Robert Jasiek
x = move with number x
Vy = variation with number y
Vy/x = move x in variation y
(player_B is Black.)
11: Although the principle idea to force before invading is good, does it work well?
V1: A few decades ago, books were telling their readers that Black should play at 11 because he invades in sente and afterwards has good follow-up moves at A or B.
V2: However, White can fight back. The ladder V2/17 at V2/18 does not work. It is hard to imagine a good result for Black afterwards.
V3: This would be another ladder failure for Black.
V4, V5: Black is heavy.
V6: The exchange V6/19-20 is essential.
23: very bad because it takes gote unnecessarily.
25: This is not optimal. The solid connection is correct.
V7: Black has about 6 points in the corner because the atari is Black's privilege and either player might get the other turn and connection endgame. V7 is the best endgame.
V8: Black dead.
V9: Endgame calculation: Black has 4 points in the corner. Each player captures 1 stone. The possibility of a captured ko stone may be assessed as 1/3 point for Black. White loses 1 more point on the marked intersection because Black's push will be his privilege. So altogether Black gets 5 1/3 points in this variation. This is worse than V7.
V10: Endgame calculation: Black has 2 points in the corner. Black captures 1 stone more than White does. White loses the additional, marked point. Altogether Black gets 4 points in this variation. This is worse than V7.
V11: Endgame calculation: Black has 2 points in the corner. Black captures 3 stones more than White does. The possibility of a captured ko stone may be assessed as 1/3 point for White. Altogether Black gets 4 2/3 points in this variation. This is worse than V7.
V12: Endgame calculation: Black has 3 points in the corner. Black captures 1 stone more than White does. Either player might get the single stone endgame. If Black gets it, this gives an additional 3 points; if White gets it, this will be an additional minus 1 point. The average of these two is plus 1 additional point for Black. Either player might get the turn and connection endgame (average: 0 points). So altogether Black has 3 + 1 + 1 = 5 points in the corner on average. This is worse than V7.
28: If White does not like the game continuation, 28 might also be played on the fourth line or as in V13.
V13: This constructs White's moyo.
39: This and the associated strategy (reduction and defense also on the other side with 41) are possible but other moves like H10, G14, or K13 and strategies are also possible.
41-43: The sequence looks so plainly ordinary that it deserves further study. 43 is a good move with good timing. 41 and 42 may be called natural. But what about alternatives?
V14: White takes sente to invade. Since V15 and V16 are doubtful for Black, V14 can be expected. The continuation from V14/45 is just an example, in which White chooses a light reduction in sente. Note that Black can still invade C17 later.
V15: Black prevents White's sente but this is bad style: Black's shape is weak while White's is very strong.
V16: The exchange V16/47 - 48 does not help Black's shape much, either. Rather it blocks an escape route for Black's center group.
41: So the preliminary conclusion is that 41 is not necessarily sente. Can Black do better? G14 would be similar.
V17: Black is overconcentrated. This is worse than 41.
V18: This is a reasonable alternative. Black gets a bigger moyo while White gets a bigger corner.
V19: White's play is too risky: He does not get two eyes easily.
41, 42: The moves are good but there are alternatives like V14, V18.
45: 44 prepares and attack and 45 answers: "I am not afraid of being attacked." However, this is unreasonable; see V20.
V20: White must attack. Although Black will survive somehow, the result will be very good for White: He gets much thickness in the center in sente.
V21: Black changes the topic from "Who gets which fraction of the corner?" to "Who has the initiative in the center fight?"
48: Wastes a ko threat; should be played later.
50: Reducing the black moyo from the center is also possible.
51: Bad shape and only endgame.
52: Only endgame. Better at the top, e.g. H17.
57: Overplay. Black cannot expect V23 or V24 because White will choose a variation like V22 before Black gets a chance to sacrifice well.
60: Mistake. Although V22 looks similar to 60 + 62, this is deception because 61 is another mistake.
V22: White is stronger is the neighbourhood, so he should defend by attacking. V22 is one many possible sequences. White's attack is successful: He maintains quite some territory and gets a wall in sente to nullify Black's moyo potential.
V23, V24: Black should sacrifice.
72: White has nothing to fear from attacking more strongly as in V25.
V25: stronger attack.
73+: (No comments on the endgame.)
(player_B is Black.)
8: very bad.
11: Making an overextension is inefficient because a white checking extension cannot be ignored easily. E.g., White H3 essentially requires Black to invest yet another move like M4 as a defense. 11 at L3 creates an indirect connection, i.e., where the opponent does not want to cut even after playing a checking extension at J3.
21: It does not matter that the move is uncommon is such a situation. What matters is the weakness of Black's shape, see V1, V2. F3 would have been peaceful.
V1: White spoils Black's expectation and attacks K3. Although the ensuing fight does not have a clear outcome, Black should not take an unnecessary risk.
V2: Black should not even dream of connecting at A immediately after V2/32 or later. A connection with so bad aji is a burden rather than a solution.
27: If one exchanges 25 - 26, then C1 - C3 must be exchanged as well. After 27 or 27 at G3, White D1 threatens to capture E2.
V3: If K3 were at triangle and 27 played solidly as here, then the C1 exchange can and should be kept in reserve.
29: The ordinary attacking shape moves are M5, L5, or N4. It is the amateurs' privilege to play funny shapes like 29. Nevertheless, one must verify that the shape does work. V4 - V6 show this.
V4: Black gets reasonably thick shape in the center. Since White has weak groups in the neighbourhood, he cannot activate his cutting stones.
V5, V6: These are other good attacks.
35: mistake. Instead O5 leaves behind one cutting point less and it is much less severe: no atari is available.
42: White forces himself into bad shape by pushing from behind.
V7: This is correct: White moves ahead of the black stones in the mutual run to the center.
V8: By all means, Black must block White's easy route to the center. The difference between Black V8/43 and Black 43 - White 44 at V8/43 is worth over 20 points (in comparison to the saying that a ponnuki is worth 30 points). It is so big because the difference is between Black versus White controlling the center with thick shape.
V9: White's shape attack does not work.
V10: White cannot move his cutting stone meaningfully.
44: Trying to move a very weak cutting stone loses many points. Must be at K9.
45, 47, 49, 51: Capturing or trying to capture an almost meaningless (cutting) stone helps the opponent to strengthen his shape and previously weak group on the right side. Must be at K9. Black destroys his chance to attack White's eyes at R9 later.
52, 56, 57, 75, 79, 84: Must be at K9.
53: This is dame. Even worse: The opponent gets to play another defensive stone: After 54, the last aji of R9 is gone. Playing dame while the opponent gets something (elimination of aji) loses points.
V11: If you think that 53 saves two stones in sente, consider this endgame variation versus Black starting the endgame with S6: If 53 should have made sense, Black needs to answer V11/56 at V11/57, making 5 points in gote. On the right, White makes 7 points in sente and prevents a similar amount (for the sake of simplicity, let us guess: another 7 points) in reverse sente. So the endgame is 5 points in gote for Black versus roughly 14 points in (reverse) sente for White. Using the rule of thumb that sente endgame is worth twice the same amount of a gote endgame, White makes roughly 28 points in gote compared to Black's 5 points. Of course, this calculation is imprecise and Black can do better than V11/57 but you get the idea: Move 53 is not just played on a dame but also very bad endgame. If you don't like numbers, you can get this insight also from a simpler perspective: What is the purpose of saving the stones P7 + P8 during the middle game? There is none. They do not cut, attack, defend, nor protect eye space.
V12: If Black replies naively, then something works.
V13: Therefore Black plays more defensively and White cannot cut. White's local endgame advantage cannot equal Black's tenuki at V13/55.
V14: Black can also defend locally while avoiding the overconcentration of 55.
57: A checking extension in front of a 4th line moyo constructor is scarcely efficient.
V15: This is an example of an efficient reduction of White's upper moyo. First Black leans on White's lower group to strengthen himself. Then he plays the local double sente V15/63. Because Black can now run towards his wall, V15/65 can be a line deeper than 57. With V15/66, White cannot defend everything and so Black gets, e.g., also the efficient V15/67.
V16: Probably White will try to complicate things but, if Black is flexible, White won't get a convincing result, either.
58: Nice punishment for neglecting to prepare the reduction.
59: Black asks for trouble.
V17: The ladder does not work for Black and the ladder breaker is not particularly serious. This is a success for White.
61, 63: nice combination.
65, 67: overdo the lightness.
V18: Black cannot be killed or attacked strongly.
68: Defends an almost useless stone (O15). Should be at L13.
78: White should play V19 to prevent Black's sente follow-up if 79 is at D18.
79: Locally better D18. (Hint for a possible conceptual idea: If one takes gote in an endgame, then at least the follow-up should be sente.)
83, 84: should take sente.
87: Do you jump headfirst into an unknown, dark water? Deep invasions need preparation!
V20: This is a possible preparation.
V21: Without preparation it is unclear what will happen.
[Note: Normally there are some 20 variations per game. The much greater number of variations here is just an accident caused by the reviewer's curiosity.]
(player_B is White.)
15: Better at G16.
16: overextension. One should not regard 16 - 17 a forcing exchange because 17 has made a later invasion of White M17 much more difficult.
V1: This way the white stones maintain their connection.
17: too kind.
V2: Being enclosed like this early in the game is very bad for White.
19: After 20, it is hard for Black to avoid overconcentration. After 31, C9 and E9 are almost superfluous. Therefore one wants to place 19 so that C9 and E9 work more efficiently. However, this is not easy, too, as V3 shows, where White can aim at the reduction exchange A - B later. So, for an evaluation of C9 and E9, one should broaden one's view by comparing them with C11 and C13: White is even more overconcentrated. In other words, 20 is to be expected and Black has to become somewhat overconcentrated. All one can really do is to minimize the impact.
V4: Black cannot play this variation because of the ladder.
V5 - V8: White success.
V9: Later White can play A - D in sente. V9 is better for Black than the game.
V10: This variation is slightly worse for Black than the game because White's upper left group cannot become weak any longer. - Summary of the variations: The game sequence 21 - 31 is the best choice.
32: The invasion is too early and helps the opponent.
V11: Maybe White is afraid of losing sente but if so, then White can choose something like V12.
V12: White reduces the top in sente and constructs influence on the right side while reducing and leaning on Black's major moyo.
V13+: These variations exemplify why 32 is bad. Many other, similar variations could be imagined but they are all good for Black.
33: This is too soft.
V13: V13/33 is the strongest move. Up to V13/45, Black gets an impressive wall.
V14: White cannot get a good result.
V15: Even if Black plays peacefully, he gets an impressive wall.
V16-V19: Black gets an impressive wall.
V20, V21: Sometimes these alternatives are possible. However, here the results may be playable but are not clearly favourable for Black. Therefore he should prefer V13/33, which leads to a favourable position necessarily.
V22+: The question is whether V22/39 is better than the game.
V22: White is heavy.
V23: Black is clearly better.
V24: Black gets much territory but does not clearly win the game yet. B does not choose this.
V25: Black is better.
V26: White loses too much.
V27: White's shape is doubtful.
V28: This is a disaster for White; he does not choose this.
V29: This is a White success; Black does not choose this.
V22+: Conclusion: Black can do even better than in the game up to 48.
41: Can Black do better by capturing?
V30: Black is captured.
V31: White is captured and White's thickness is not enough compensation.
V32, V33: Black will not play this.
V34: This does not work for White.
V35: White has no hope to improve on liberties.
V30-V35 conclusion: Black is better.
V36-V38: Black wins.
V39-V41: White wins.
V36-V41 conclusion: White wins. Therefore V42 is necessary.
V42: White is still in the game.
V43-V44: White wins.
V45-V46: Black wins.
V47: White is still in the game. Black chooses V48 though.
V48: Black has thickness and sente, so this is favourable for Black.
V45-V48 conclusion: Black is better.
V43-V48: conclusion: Black is better.
V49-V52: Black wins.
V30-V52 conclusion: Due to V36/48 and the ensuing variations V36-V42, Black cannot do better than 41, can he...?
V53: There are many more variations to be studied. So the preliminary conclusion is: 41 is a good, steady move if one cannot calculate all the variations. At least all those variations also show that the invasion of 32 is doubtful.
47: This is bad shape because some time White can peep two spaces to the left or two spaces to the right.
V54: This is better shape. Even after a White peep, Black still has good eye shape potential.
48: Locally this is not small but developing the lower right is bigger because the space there is wider and because it threatens to reduce Black's major moyo.
51: This is inconsistent. Instead it should develop the moyo.
52: Overplay, too deep. The basic idea is right though: to reduce Black's moyo.
V55: This is an example of a light reduction and builds a white moyo in the meantime.
V56: Killing is not possible but Black risks to lose most of his moyo if tries to attack.
57: Better capture immediately. Otherwise White can atari to reduce the major part Black's moyo then.
58: Taking the corner is smaller than reducing Black's moyo.
60: Although the move is necessary to complete the sequence, the result is a success for Black: White has taken 19 points in the corner that is still open along the side and so can be reduced later while Black has got sente to increase the territory value of his moyo by significantly more.
62: This is too deep and 63 is a nice punishment.
V57: Simple and reasonable.
64: Setting up aji for escaping is a possible plan but...
66: ...is yet another heavy stone.
V58: White would get better shape for defending his center group. That the upper left group is hurt cannot be avoided; it is a consequence of White's too deep invasion.
71: H10 is not in urgent need of defense. M10 would attack the most harshly.
V59: Black still can defend H10 while White's groups don't know what to do next.
72: Too heavy. Better M9.
73: Better M9.
74: Too heavy. Better M10.
V60: V60/77 is better than 77+79. The variation is just an example to show how difficult it is for White to survive with both groups: White's center group still does not have two clear eyes.
82: Such bad shape does not work.
V61-V62: This refutes 82. White cannot hope to live.
87: Bad aji. Better H6.
91: Unnecessary. Should defend the center group.
V63: Defends the center group.
V64: Black fails.
V65-V67: White is dead.
taking gote unnecessarily 1/23, 2/83
heavy 3/66, 3/72, 3/74
failing to move ahead in a shape run towards the center 2/43, 57, 75, 79
forgotten to stabilize shape 1/19
creating bad shape unnecessarily 1/51, 3/82
suboptimal endgame 1/25
playing mostly endgame moves too early 1/51, 3/58
attacking unimportant stones or playing dame 2/47-53
helping opponent's weak stones 2/47-53
invasion helps opponent 3/32
Unlike quite some other players, you do not have several major weaknesses but many different minor / intermediate weaknesses. Although this means that you should study all those aspects of the game (gote, efficiency, moving ahead, shape and its completion, endgame and its timing, relevance of stones, helping yourself instead of the opponent, etc.), they have something in common: You do not pay enough attention to details. Do not make just some move for a particular purpose but make the best move for it!
not making the necessary reading before playing an uncommon move 2/29, 2/87
probably not considering enough alternative strategies 1/41, 1/45
Knowing in advance what will happen is essential for choosing the locally right move, its timing, or the globally best strategic choice. Invest more energy in reading ahead and consider more move alternatives during the imagined move-sequences! The variations give you examples of what to think about in complex situations.
overplay 1/57, 2/11, 2/21, 2/59, 2/65, 2/67, 2/87, 3/16, 3/52, 3/62, 3/66, 3/88
This is your most frequent type of mistakes. Before you make a move, verify whether it is indeed possible and whether it does achieve the desired purposes. This requires reading ahead that replaces dreams by facts. Your overplays are scarcely of the careless nature but are of the not sufficiently studying the details (the verification by reading) nature.
All your mistakes have something in common: You do not invest enough attention and effort in details.
Therefore you should change the way or method of thinking and planning about deciding on your next move (each of your moves!): Have I verified that it does work, achieve its aims, and agree to the aspects of go theory?