Software Vault: The Diamond Collection

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Text File | 1995-01-21 | 42KB | 1,136 lines

EVENT BOARDSIZE 19 COM ....................... ! ! ! To get started with ! ! game & commentary:- ! !. . . . . . .! ! Hit down/up arrow ! ! for forward/ back ! !. . . . . . .! ! PgUp/Dn to jump10 ! ! Home/End to ends. ! !. . . . . . . .! ! Right arrow -> for ! ! more information ! ! where indicated. ! !.....................! ENDCOM B 1 r16 COM B1: A board corner is the easiest place to defend because the board edges make two sides of potential eye-space to begin with. So it is very common to see each of the first four moves in a separate corner. Black #1 is on a `3-4' point. This is the most common opening move because it has several good follow-up moves. ........................Note: Lines are counted inward from the nearest edges. This includes the edge-of-the-board line. (01/95) ENDCOM W 2 c17 MARK All UNMARK r16 COM W2 The 3-3 point move in an empty corner like this is good for territory. One move makes a very secure situation for White. .................... Note: Although this tight-in-the-corner move makes the corner hard for Black to attack, it has weak "influence". ------------------------ Use -> for definitions ------------------------ ENDCOM VAR DIAGRAM SETUP W c17 COM "Influence": The impact which a stone may have on near-by board points. This is generated by strongly cooperating stones. Such stones may participate in enclosing future ter- ritory but they are primarily useful in limiting the opponent's options for good moves in the near-by area. ----------------------- Use <- for back to main ----------------------- ENDCOM ENDVAR B 3 q3 MARK W@r5 B@q8 q3 3@q3 r16 COM B3 This move cooperates nicely with B1. ..................... Note: If White were to approach B3 at `r5', marked `W', (a common corner approach move), Black could then `squeeze' White `W' by playing at `B'. This move is a proper ext- ension from B1 above. It leaves very little room between `B' and `1' for White to form a `base'. ----------------------- Use -> for definitions. ----------------------- ENDCOM VAR DIAGRAM SETUP B q3 MARK 3@q3 W@r5 B@q8 COM Definitions:- "Squeeze" = A play which confines an enemy stone or stones in a manner which makes it difficult for him to do what he would like to do next. "Base" = A loosely enclosed area which has the potential to form two eyes when needed, usually between a group of stones and the edge of the board. ----------------------- Use <- for back to game ----------------------- ENDCOM ENDVAR W 4 d3 COM W4 The last corner. Getting the first move in an open corner is top priority at the start. ...................... Note: Each corner move is placed where it can easily make a "base" when attacked on one side, by moving out to the other side to start forming a "base" there. ENDCOM B 5 p17 MARK r16 COM B5 This `knights move' from B1, called "Keima", (pronounced key-ayma) makes an ideal shape in the corner. ....................... Note: This corner form- ation can make two eyes easily. But more impor- tant is it's `influence' *Influence*: The impact a stone has on near-by board points. This is generated by strong and cooperating stones. It may turn into territory but it is most useful in limiting the opponent's options for good moves. ENDCOM W 6 r5 MARK w@r8 W@s3 x@s3 y@q4 z@r8 W@q5 All UNMARK r16 c17 q3 d3 p17 COM W6 This approach move is normal in this situation. It keeps one line away from the Black stone. ....................... Note: W6 was played low, on the 3rd line, so White can now create a base along the right side whenever that might seem appropriate. This `low move', as opposed to `W', leaves the corner open to a later attack by White, at `x' or at `y'. ENDCOM B 7 q9 MARK d14 d14 \t@p17 \t@r16 COM B7 Squeezes White's single stone below. .................... Note: B7 cooperates nicely with the two marked Black stones above. This restricts any White attempt to make a base on the right side between B7 and the two marked Black stones. Hence this is called a "squeeze" play. ENDCOM W 8 q4 MARK A@p3 COM W8 This is the best approach to building a White base in the lower right corner. This is a "Sente" move. ........................Note: Black must respond because otherwise White could easily grab the whole lower right corner by playing at `A'. *Sente* (spoken: senteh) A move which is so threatening to the opponent that he needs to respond defensively. Thus the attacker keeps the initiative. ENDCOM B 9 p3 MARK \t@q3 W@r3 q4 COM B9 Black saves his threatened stone. He can now safely create a base along the bottom. ................... Note: White 8 was "sente" because it took a liberty away from the lone marked Black stone. An answer by Black was urgent. Without the extra liberties which Black gained from this attachment White could have attacked the marked Black stone, at `W' for instance, or even at the B9 point, and thus have taken the whole corner. ENDCOM W 10 r3 MARK q4 COM W10 This was a key point for both players. Whoever got there first would have a secure "base" in the corner. ....................... Note: White was able to get this move in ahead of Black because he forced a Black defense with his W8 move. ENDCOM B 11 r2 MARK B@s3 B@s4 C@s3 r3 COM B11 A Key move as Black still needs a base. ........................Note: Black gets part of the corner and aims to form a base along the bottom edge of the board. This Black move is Sente. It threatens to attack W10 at `B' or at `C'. That would make it very hard for White to make a base here. ENDCOM W 12 s3 COM W12 The only proper move. It assures eye space for White in the lower right. ...................... Note: Otherwise Black could seriously squeeze out White's important corner base by playing at W12 next. ENDCOM B 13 m3 COM B13 This is a key point as it is necessary for Black to assure a base along the bottom. ....................... Note: Given the chance, a White squeeze-move here at this B13 point before Black played there would have been devastating to Black. - - - - *Each player must always be alert to the threat of such a squeeze move early in the game. ENDCOM W 14 c5 MARK p17 s3 COM W14 This is a big move. It is comparable to B5 in the upper right. ..................... Note: Keeping sente with W12 in the lower right encounter made this White lower left initiative possible. ENDCOM B 15 f16 MARK A@f17 d14 B@d14 \t@p17 \t@r16 \s@c17 B@e17 C@d14 COM B15 Common approach to a single opposing stone at the 3-3 point. (B15 at `A' or `B' would be equally effective here.) ...................... Note: the option of B15 at `C' right now would be very effective in disrupting potential White territory along the left side, but Black's potential along the top is greater because B15 cooperates well with the upper right marked \t stones. ENDCOM W 16 d14 MARK \t@c5 \t@d3 \s@c5 \s@d3 c17 COM W16 White must now move out away from W2 to assure a base here. ..................... Note: W16 cooperates nicely with the two marked White `\s' stones below. (If Black had gotten to the W16 point before White he could have squeezed White into a very small corner area, and thus also reduced White's potential along the left side. ENDCOM B 17 j16 MARK \t@p17 \t@r16 f16 COM B17 An ideal two space extension from B15 and the "five line space" from B17 to the nearest upper right marked Black stone is perfect. ...................... Note: Taken together with the two marked Black stones in the upper right corner, White's options for future invasion along the top side already appear to be severely restricted. ENDCOM W 18 r11 MARK q9 W@p11 B@q9 q9 COM W18 This move makes a good start at elimin- ating Black's potential along the right side. ................... Note: This move is Sente. It obliges Black to answer because it threatens B7. (If Black were to play elsewhere now and White played at "W" Black would be in real trouble because there would be almost no room for him to make a base along the right side. ENDCOM B 19 r13 MARK W@d10 r11 COM B19 This is a valuable move. It squeezes W18 and greatly improves Black's upper right influence. ...................... Note: It's White's turn. He could now abandon W18 and play at `W' instead. This would tend to equalize opposite sides of the board. . ENDCOM W 20 p4 MARK p18 A@o3 \s@p3 \s@q3 \t@p3 \t@q3 *@q9 COM W20 This is good timing. White's right side group has been in need of help. This move is Sente. White is now much more secure. W20 takes away a liberty from the two marked Black stones. .................... Note: Black's whole corner group is threat- ened now. ENDCOM VAR DIAGRAM SETUP W p4 MARK 20@p4 SETUP W s1 MARK \t@p3 \t@q3 \t@r2 SETUP W o3 MARK W@o3 COM If White gets a chance to play at `W' he can collapse Black's whole corner group marked `\t'. . . ----------------------- Use -> for more detail ----------------------- ENDCOM ENDVAR B 21 o4 MARK \t@m3 \t@p3 \t@q3 \t@r2 COM B21 This is necessary because Black's lower right group would be vulnerable otherwise. ...................... Note: Black's move on the 4th line has the advantage of restraining White's thrust toward the center. (i.e: It gives Black more upward influence.) ENDCOM W 22 o5 MARK w@o3 W@o3 A@o3 o4 COM W22 This is a forcing move. Black is vulner- able to attack at `A'. ..................... Note: This is a `lean- ing' attack. It reduces the B21 liberties. If Black were to play else- where now a White move at "A" could destroy Black's whole corner. So Black must respond. . . . *Leaning*: Making con- tact with an opponent's stone in a way that obliges the opponent to answer, and/or which keeps him from extending in an unwanted way. ENDCOM B 23 n4 MARK q2 s2 d9 o4 COM B23 Necessary because of cutting point problems if B21 were left undefended. .................... Note: Black 21 was short of liberties and vulnerable. Now Black has strengthened his base and his outward influence considerably with this single move. . . . (The attack point shown shown in the previous screen is no longer effective.) . . ENDCOM W 24 p11 MARK \t@q9 \s@p17 \s@r16 \s@r13 B@p17 B@r16 B@r13 \s@p17 \s@r16 \s@r13 MARK r11 *@q9 \t@p17 \t@r16 \t@r13 COM W24 An important move which squeezes and attacks the marked Black stone `*', and saves W18 by extending toward the center. . . ENDCOM B 25 o8 MARK \t@q9 COM B25 Black now must move out toward the center. He cannot make a base on the right. ..................... Note: If White now plays correctly there will not be enough space along the right side for Black to make even one eye there. ENDCOM W 26 o10 MARK \s@p11 \s@r11 COM W26 A natural squeeze. It also helps with the defense of the two stone white group marked `\s'. ..................... Note: This move puts pressure on the two Black stones by taking a point which would have been very useful for Black. ENDCOM B 27 q6 MARK A@p5 \t@o8 \t@q9 COM B27 A useful forcing move. It threatens to cut White's group at at A. It is a very effective Sente move against White. ...................... Note: This cooperates with Black's two marked stones above, and the threat of a Black cut at `A' insures a White response. ENDCOM W 28 r6 MARK A@p5 w@p6 \t@o8 \t@o8 \t@q9 \t@q6 COM W28 White protects the cutting point and gets more eye space along the right side at the same time. . ....................... Note: Now White can make two eyes along the right side, regardless of the unsettled eye space in the corner. (Because of W28 a Black stone at A could be captured immediately by a White move at `w'.) . . So Black must find some other way to strengthen his nearly surrounded three stones marked `\t'. . . . ENDCOM B 29 q7 MARK \t@q9 \t@o8 \t@q6 A@p5 a@p6 \s@o10 \s@p11 \s@r11 COM B29 This helps all three Black stones, marked `\t', by increasing Black's available liberties and makes the cut at A an effective threat again. ...................... Note: This move also prevents what could have been a painful cut by White at the B29 point. Playing at `A' or `a' will defend against the cut at A and will help White keep the two Black groups separated, but it would allow Black to separate the three White stones, marked `\s'. ENDCOM W 30 r8 MARK B@r9 COM W30 This is a defensive move. White hopes to connect his upper group with the one below. ...................... Note: W30 can still connect to the upper group unless Black cuts him off at `B'. Either way Black has no eye space along the edge, and White still has no full connection between his groups. So White could become burdened with a separate no-base upper group to defend. ---------------------- Use -> for more detail. ---------------------- ENDCOM VAR DIAGRAM SETUP W r8 MARK \s@o10 \s@p11 \s@r11 \t@p4 \t@q4 \t@r3 \t@s3 \t@r5 \t@r6 MARK Y@p5 30@r8 \t@q9 \t@o8 \t@q7 \t@q6 \s@m3 \s@n4 \s@o4 MARK \s@p3 \s@q3 \s@r2 ?@o5 X@s9 W@r6 W@r5 W@p4 W@q4 W@r3 MARK W@s3 B@m3 B@n4 B@o4 B@p3 B@q3 B@r2 COM The White group marked `W' can make two eyes when needed. But he must play at `X' to solidly connect with his group marked `\s'. Black must play at `Y' in order to assure that the `\t' group can connect with the `B' group below. The stone marked `?' probably could not survive after a Black move at `Y', so a connection can be achieved. It is Black's turn. He must choose. ----------------------- Use <- for back to game ----------------------- ENDCOM ENDVAR B 31 p5 MARK \t@o8 \t@q9 \t@q7 \t@q6 COM B31 This cutting move allows Black to connect his upper and lower groups here. ...................... Note: This Black move is "Gote" but it assures that the marked Black group can connect to the lower Black group. It is certainly worthwhile to give sente to White at this point. ENDCOM W 32 s9 COM W32 White makes a solid connection between his upper and lower groups. ...................... Note: This engagement has turned out well for White, but it is better for Black since he now has strong center influence. ENDCOM B 33 c12 MARK A@d11 \t@c17 \t@d14 COM B33 This is the biggest move on the board right now because the left side is wide open and White's formation is not strong yet. ........................Note: B33 squeezes the marked White corner group and is sente, so he will have time to establish a left side base. B33 is also preempting a potential White move at or near `A'. That would have greatly hampered Black's options along the left side. ENDCOM W 34 c14 MARK \t@f16 \t@j16 c12 COM W34 This move makes a complete base for White in the upper left corner and it is necessary now ....................... Note: Without B34 White would be vulnerable in the corner because of the near-by marked Black stones. But this move also attacks B33 so it is sente. ENDCOM B 35 c9 MARK A@c10 COM B35 This move makes a base for Black, and it is necessary. ...................... Note: Black now has a beginning for eye space along the left side. Without B35, a White stone at A would have been a big gain for White and a severe attack on Black. . ENDCOM W 36 g3 MARK B@h3 A@h3 COM W36 This appears to be a slow move but in fact it is the right move for White now because Black's lower right group is already strong. .................... Note: Extending any further, say at `A' or beyond, would have invited a Black invasion supported by his lower right strength. A pre- emptive Black move at `A', would have been a very severe set back for White. ENDCOM B 37 m16 MARK \t@f16 \t@j16 \t@p17 \t@r16 \t@r13 \s@p17 \s@r16 \s@r13 \t@p17 MARK \t@r16 \t@r13 g3 COM B37 This is the biggest move on the board now. ...................... Note: Its proximity to the upper right group makes the potential for Black territory along the top VERY substantial - - - - Moves #36 and #37 are `Miai' (pronounced `me-eye'). This is a situation in which two open moves are equal in value. When one is taken, the opponent will usually take the other. ENDCOM W 38 c7 MARK \t@c12 \t@c9 COM W38 This also seems like a slow move but it squeezes Black's left side marked group and it strengthens White in the lower left corner. ENDCOM B 39 j3 COM B39 This is the last big move on the board now. It ends the "Fuseki" (foo sek ee). ..................... *Fuseki*: "The opening phase of a game of Go." ENDCOM W 40 n7 MARK \t@p5 \t@q6 \t@q7 \t@q9 \t@o8 W@o5 COM W40 This is called a "reduction move". It aims to prevent Black from obtaining excess- ive center influence. .................... Note: If White could keep his cutting stone `W' alive the separated Black group would be in great trouble. Since he cannot do this, he hopes to use W40 to confine Black's potential here. Hence the term `reduction'. ENDCOM B 41 n8 MARK \t@o8 \t@q9 \t@q7 \t@q6 \s@n7 \s@o5 COM B41 A big help to the marked Black group. ....................... Note: It separates the marked `\s' White stones from the White group above, and it also is a big help to the marked `\t' Black group. The two marked White stones are in trouble. . . . (If White now tries to save these two marked stones and Black re- sponds properly the two White stones will be captured and Black will end up being immensely stronger in the center.) . . ENDCOM W 42 l7 MARK @o5 p5 q6 q7 q9 o8 n8 \t@n8 \t@o8 \t@q9 \t@q7 \t@q6 MARK \t@p5 \s@o5 \s@n7 COM W42 White makes a light `running' move toward the center. ...................... Note: White hopes W42 may prove threatening to Black and thus help White to keep Black out of the center. White's two marked stones remain quite vulnerable. . . *Running*: A loose move usually aimed at helping a threatened group to reach toward the center where there is far less danger of capture. ENDCOM B 43 m8 MARK @o5 @n7 @l7 \s@l7 \s@n7 \s@o5 COM B43 A key point. It strengthens Black and weakens White. .................... Note: White needed to be on this point before Black. Now White's three stone group, marked `\s', is being squeezed badly by Black. ENDCOM W 44 j4 MARK \t@g3 \t@l7 \s@l7 \s@g3 j3 COM W44 The best play for White now. He is `leaning' on B39. ...................... Note: This will enable White to connect his two marked `\s' stones. ENDCOM B 45 k4 MARK \t@j3 \t@o5 j4 COM B45 This is the natural Black response. It helps the marked `\t' stone, which was weak. Note: Now White 44 is weak. It has only two liberties, whereas the two Black stones it touches each have three. Also, Black is still making sure that White does not find a way to rescue the vital marked White cutting stone. ENDCOM W 46 j5 MARK \t@l7 A@h4 \s@l7 j4 k4 COM W46 This move, or at A, are the natural defens- ive moves for White, but W46 is best because it reaches toward the marked White stone above .................... Note: White 44 was threatened by B45. This White move overcomes that problem by increas- ing his liberties there and it continues his aim to eclose territory to the left of 44/46. ENDCOM B 47 h3 MARK \s@g3 \t@h3 \t@j3 47@h3 COM B47 A good forcing move. It takes a liberty away from the single White stone, marked `\s', and increases the liberties of the Black twosome. .................... Note: B47 is double Sente for Black and it starts a painful invasion into what had appeared to be White's territiory. Now what ever White does, Black will still have Sente. So he will continue reducing White's pot- ential territory in the lower left. ENDCOM W 48 g4 MARK \t@g3 \s@g3 COM W48 This is the only move for White now. ..................... Note: This move adds liberties to the marked White stone and also restrains Black from pushing further into White's potential lower left territory . ENDCOM B 49 k5 MARK \t@l7 \t@n7 \t@o5 j4 j5 COM B49 A double forcing move by Black. ....................... Note: It takes away one White liberty from W44/46 and threatens to push on into the center, cutting off the three marked white stones. ENDCOM W 50 k6 MARK \t@l7 W@o6 k5 \s@o5 COM W50 The only proper response to B49. This move is Sente. ....................... Note: This White move helps assure a con- nection with the marked White stone above and blocks the Black thrust toward the center. It is Sente because, if Black were to play elsewhere now White could play at `W' and thus maintain the marked cutting stone and that would keep the eyeless upper Black group separated from the strong lower Black group. ENDCOM B 51 n5 MARK \t@m8 \t@n8 \t@o8 \t@q9 \t@q7 \t@q6 \t@p5 \s@o5 COM B51 Now Black can connect his upper group, marked `\t', to the lower Black group whenever he wishes. ..................... Note: This is a gote move but it is worth it now. Thus Black will now be free to push into the center from the upper Black group, marked `\t', with no need to worry about making eyes there. ----------------------- Use -> for more detail. ----------------------- ENDCOM VAR DIAGRAM SETUP W o6 MARK \t@p5 \t@q6 \t@q7 \t@q9 \t@o8 \t@n8 \t@m8 \s@o5 51@n5 MARK W@o6 COM Note: Before B51 a White play at `W' would have saved the cut and thus kept the marked Black group isolated. (But Black has kept White busy and he has had no opportunity to make this key move.) . . ----------------------- Use <- for back to main ----------------------- or, -> for more detail. ----------------------- ENDCOM ENDVAR VAR DIAGRAM SETUP B n5 MARK 51@n5 \s@o5 \t@n7 W@o6 B@m7 COM The stone at `\s' was played there to separate the eyeless upper Black group from the lower group. Now it's useless. . . If White plays at `W', then Black at `B' all 3 white stones are dead. So, after B51, White should recognize that he cannot now save his cutting stone at `\s'. He has Sente and will play elsewhere. ----------------------- Use <- for back to main ----------------------- ENDCOM ENDVAR W 52 e8 MARK \t@c14 \t@d14 \t@c9 \t@c12 \s@c14 \s@d14 COM W52 This move develops the center area and also squeezes the left side Black group. ..................... Note: The White two stone `post', marked `\s', combined with W52, will make it difficult for Black to build a secure base. ENDCOM B 53 b13 MARK \t@c9 \t@c12 COM B53 Black makes a defensive move to increase his potential eye space here. ...................... Note: This Black form- ation still has a weak- ness and so he can not be sure about the necessary two eyes here. Because of this White will continue to squeeze Black. White aims to strengthen his structure in the process and thus to increase his center area potential terrotory . . . ENDCOM W 54 b14 MARK \t@c12 \t@c9 COM W54 White takes a key point away from Black and strengthens White's corner form- ation. This move is Sente. ....................... Note: Black's base does not yet have secure eye space. See explanation on the following screen. ENDCOM B 55 e12 MARK 54@b14 COM B55 Helps confine White's upper-left corner group and reaches out toward the center. ....................... Note: White has loosely enclosed a very large potential territory in the lower left quadrant. Black aims to reduce this as much as he can. However, if Black can not make another eye in the center he must make sure of two eyes within his rather loose left side base. ENDCOM W 56 f14 COM W56 Separates the two Black groups. .................... Note: White is also aiming to improve his opportunities to reduce Black's potentially large territory in the top center of the board. ENDCOM B 57 d17 MARK B@c18 COM B57 This is a clever forcing move. It attaches to a strong White shape in a way that is Sente. ....................... Note: All this fighting is very close to the wire. If Black were able to play at `B' now White would be in serious trouble! (Because White would have only enough space for one eye). ENDCOM W 58 d16 MARK \t@c17 \s@c17 COM W58 White must protect his corner and this is a proper answer since White's stone, marked `\s', was weak. ....................... Note: White must remain secure in the corner but also it is urgent that he find a way to reduce Black's large potential territory along the top. ENDCOM B 59 c18 MARK B@e17 COM B59 This is a special situation. Black moves to squeeze White in the corner. But Black still must aim to block White pene- tration into his loose framework at the top. ..................... Note: Normally Black would play at `B' to solidly defend his upper side enclosure, but what he is doing here may help Black's final score. (Black gambles on his ability to correctly read out the outcome in this complicated situation.) ENDCOM W 60 e17 MARK c18 d17 COM W60 This is the only move that can separate Black 57-59 from the large Black group at the top. This White move is Sente. ....................... Note: Black must answer or he will lose the whole corner. Otherwise White can simply capture Black 57 now in atari and thus retain the whole corner. ENDCOM B 61 d18 COM B61 Black connects and obtains four liberties for his three stone group. ENDCOM W 62 e16 MARK e17 COM W62 White connects, to save W60. ...................... Note: White is prepared to give up the corner to Black in exchange for penetration into Black's large territory at the top-center. ENDCOM B 63 e18 MARK A@c16 d17 d18 c18 \t@c18 \t@d18 \t@d17 COM B63 The natural move, since Blacks three stones, marked `\t', needed more eye space. ....................... Note: Black can make two eyes in the corner at any time as long as White leaves the cutting point at `A' open. ENDCOM W 64 f17 COM W64 White continues his push into Black's open formation at the top. ..................... Note: This thrust threatens to keep the two Black groups at the top separated, and thus helps to reduce Black's potential territory. ENDCOM B 65 c16 MARK \s@c17 COM B65 Atari. Black can now capture the marked White stone and make two eyes in the upper left corner whenever he wishes. ...................... Note: The marked White stone cant be saved by playing at b17 because Black would play at b16. ENDCOM W 66 q17 COM W66 This is a "probe" by White. He is asking for a Black reply so he can determine how best to go further once Black commits himself. ...................... Note: This is sente, a threat to make life in the corner. White is seeking a way to reduce Black's upper right corner. As long as he can find sente moves here he runs no risk that Black will go back and stop White's push into Black's potential territory at the top. ENDCOM B 67 q18 MARK q17 COM B67 This is the correct answer. Black needs to protect the corner area even more than to stop White's push into the top center area. ..................... Note: White does not need to respond to this move since the only purpose of W66 was to ask for a response. This stone can be abandoned when Black responds. However a probe move must always be Sente. The opponent must not be free to move where ever he likes. ENDCOM W 68 p18 COM W68 Another `asking' move or `probe'. ....................... Note: White makes things more complicated and thereby hopes to create opportunities to reduce this large Black corner area. ENDCOM B 69 o18 MARK p18 \t@q18 COM B69 This is the proper answer. Black takes away one White liberty and puts White in atari. ...................... Note: If Black were to ignore W68 White could play at r18 and capture the marked stone, thus having a good chance to make life in the corner. ENDCOM W 70 d10 MARK c10 \t@b13 \t@c12 \t@c9 \t@e12 COM W70 This is an attack move which threatens Black's eye space and hence requires a Black response. ...................... Note: This Black group, marked `\t', is squeezed from both sides. White's W70 threatens to invade Black's eye-space. Since Black cannot be sure of a second eye in the center, Black must now make his left side group into a viable two-eye structure. ENDCOM B 71 c10 MARK \t@c9 \t@c9 \t@e12 \t@c12 \t@b13 COM B71 Assures connection with the Black stones above and it improves the prospect of creating two eyes along the left side. ENDCOM W 72 d11 COM W72 White takes the key point of Black's eye shape. ....................... Note: Black would love to have gotten to the d11 point before White. That would have solved his weakness, i.e: As things stand, if White attacks before Black defends, White can squeeze Black's base down to only one eye. ENDCOM B 73 d12 COM B73 A "must" move. It assures that Blacks' stones will stay con- nected and allows him to push on into the center. ...................... Note: Otherwise White would cut at d12, secure a large center area, and threaten to kill Black's left side group. ENDCOM W 74 f11 MARK d10 d11 COM W74 Cooperates with 70 and 72. White is aiming to secure a large area in the lower left center. ENDCOM B 75 f12 MARK f11 COM B75 Black keeps push- ing into the center with sente moves. .................... Note: B75 is sente because W74 has been weakened by the contact of B75. ENDCOM W 76 g11 MARK f11 W@g12 B@e11 COM W76 A natural move. It adds liberties to W74 and protects against a Black cut at `B'. ...................... Note: W76 strengthens White's shape and improves his prospects for enclosing sizeable center territory below. It also threatens to cut off Black's thrust into the center by playing at `W'. ENDCOM B 77 g12 MARK W@b17 \s@c17 w@b17 b@b16 COM B77 Black continues to push out into the center area. B77 also threatens to cut off the upper left White group. ..................... Note: White must now secure his upper left group. It does not yet have space for two eyes. (The marked White stone cannot be rescued. A White move at `w' would simply be followed by Black at `b' etc.) ENDCOM W 78 h16 MARK B@h14 COM W78 White assures eye space for his top left side group. This helps him to reduce Black's top center area. ..................... Note: White is endeav- oring to keep sente. Without W78, or a nearby point, White's upper left group could come under severe attack, at `B' for instance. ENDCOM B 79 h11 COM B79 This is an urgent point for Black. It helps him push into White's potential ter- ritory in the center. ENDCOM W 80 g9 MARK A@e11 \t@f11 \t@g11 \s@f11 \s@g11 COM W80 This is a normal defensive move. It is needed because of White's cutting point problems. .................... Note: Without W80 a black stone at `A' would allow a Black penetration into the center area because the two marked White stones would be reduced to only two liberties and hence vulnerable. W80 also makes White's lower center area much more secure. ENDCOM B 81 h15 MARK \t@j16 COM B81 Nice squeeze move. It helps the marked Black stone and the whole upper Black group. ..................... Note: This also puts pressure on White's not-too-secure upper left group. ENDCOM W 82 j17 COM W82 Aims to gain eye space along the top for White'e vulnerable group, and threatens to further reduce Black's upper potential terri- tory at the same time. ENDCOM B 83 h17 MARK \s@h16 j17 COM B83 This is a severe and necessary cut. White #82 was a serious threat to push into Black's large potential territory at the top. ..................... Note: This attack on the marked `\s' White will allow Black to make the rest of his top center territory secure. ENDCOM W 84 g16 MARK \t@f16 h16 COM W84 The only move. It saves W78 and assures two eyes for the upper left White group. ...................... Note: The marked Black stone cannot now escape. White will have several aggressive options, depending on Black's next move. ENDCOM B 85 g17 MARK \t@c18 \t@d18 \t@e18 \t@d17 \s@g16 \s@h16 B@f18 COM B85 A forcing move. It puts the two marked White stones in atari. ..................... Note: White needs to save the two marked `\s' stones so that he can secure two eyes and continue his effort to reduce Black's top enclosure. However, in saving these two stones White allows Black to connect his four stone group, marked `\t', by playing at `B'. ENDCOM W 86 g15 MARK \t@h15 \t@j16 COM W86 This is the correct move. It makes needed eye space and threatens both Black stones marked `\t'. ENDCOM B 87 g14 MARK \t@f16 COM B87 Good forcing move. It is Atari, also Sente. White can not ignore this atari. ..................... Note: Black has made good use of this sac- rifice stone, marked `\t'. He was able to play several forcing moves because of its presence there. (This was move #15 in the opening.) ENDCOM W 88 f15 PRISONER f16 MARK @f16 COM W88 The only move. White captures the Black stone at `\t'. ENDCOM B 89 f18 MARK \t@g17 \t@h17 COM B89 This is a must move. It saves the two marked Black stones. ENDCOM W 90 j15 MARK \t@h15 \t@j16 B@k16 COM W90 A severe double atari. It should enable White to push on into the center. ENDCOM B 91 k16 MARK A@h14 B@h14 COM B91 The correct choice. This move is more valuable than Black at `B' would have been. ....................... Note: This is the more important move because it divides White into three separate groups and secures Black's large territory along the top. ENDCOM W 92 h14 PRISONER h15 MARK W@b8 COM W92 The only move. Otherwise White's thrust into the center would get cut off. ....................... Note: W92 also continues White's pressure on the left side Black group which still does not have assured two eyes. (A White move at `W' remains a big sente threat to Black.) ENDCOM B 93 j12 MARK B@h12 h14 \t@g14 COM B93 Black's best move to defend the cutting point at `B'. ..................... Note: The marked `\t' Black stone is in atari but Black must ensure a continued thrust into the center in order to reduce White's large potential territory there. So Black must protect the cutting point at `B'. This move is more effective than just at `B' because it provides more options for Black. ENDCOM W 94 j10 MARK \t@b13 \t@c12 \t@c10 \t@c9 \t@d12 \t@e12 \t@f12 \t@g12 \t@g14 MARK \t@h11 \t@j12 COM W94 A nice move. It develops White's strength in the center and it threatens Black's left side group, which is marked `\t'. ENDCOM B 95 b8 COM B95 Secures Black's left side eye space and gains valuable territory for Black. ....................... For some time the left side Black group has appeared to be killable but Black has kept sente and not given White a chance to attack. Let's look now at the weakness in Black's left side group. ------------------------Use -> for explanation ------------------------ ENDCOM VAR DIAGRAM SETUP W h10 W a14 MARK 1@a14 SETUP B a13 MARK 2@a13 2@b11 SETUP W b11 MARK 3@b11 SETUP B c11 MARK 4@c11 SETUP W b12 MARK 5@b12 SETUP B c13 MARK 6@c13 SETUP W b10 MARK 7@b10 SETUP B b9 MARK 8@b9 SETUP W b8 MARK 9@b8 COM Prior to Black at b8 White could have reduced Black's base area to a single eye. White could start with a move at `1'. Black must respond at `2' to keep White from pushing into Black eye space. Black must answer again at White `3', etc. etc. until White at `9' clearly leaves no way for Black to make two eyes here. (Unmarked stones were in place when Black made his b8 move.) ------------------------Use <- for back to main ------------------------ ENDCOM ENDVAR W 96 p16 MARK \t@p17 COM W96 White goes back to the corner probes again. This is also a Sente move. It threatens to capture the marked Black stone. ..................... Note: White is still probing. He is seeking to find a way to reduce what seems likely to be very large territory for Black in this corner. ENDCOM B 97 o17 MARK \t@p17 \t@o18 COM B97 Black blocks a capture and creates a multi liberty group. ...................... Note: This Black move protects his top-center territory. Also, Black must not allow White to get established in this corner. ENDCOM W 98 r18 COM W98 White takes away one Black liberty and makes an atari. This move is sente, because White threat- ens to make life, (two eyes), in the upper right corner. ENDCOM B 99 q16 MARK \t@r13 COM B99 An aggressive move which threatens to capture all the White stones in the corner. ....................... Note: This move assures a solid connection with the lone marked Black stone below and thus assures Black territory on the upper right side. ENDCOM W 100 q19 PRISONER q18 COM W100 Takes one Black stone off the board and again White threatens to make life in the corner. ENDCOM B 101 s17 MARK s18 s18 s18 s18 A@s18 B@r17 COM B101 This is the key spot to reduce the White shape and make the White shape killable. ....................... Note: If White now plays at `A' Black will play at `B', or vice-versa. Thus White now has no possible way to make life in this corner. But note that White still has sente. (He has lost nothing with all these corner moves because each one was a serious threat and Black answered each White move there.) ENDCOM W 102 p15 MARK \s@q17 \s@r18 \s@q19 \s@p18 COM W102 Increases the liberties of the White cutting stone and thus separates the two Black groups. ...................... Note: The White group, marked `\s', in the upper right corner is dead, but White may have succeeded in reducing Black's potential along the upper right side. ENDCOM B 103 l14 MARK \t@p16 \t@p15 COM B103 Black jumps out to contain the upper left White group and threat- ens to cut off the two marked White stones. ENDCOM W 104 n15 MARK \t@p15 \t@p16 \s@p16 \s@p15 COM W104 Helps the marked White stones to connect with the White group below. ENDCOM B 105 r17 COM B105 This is a "thick" move which kills the White group for sure. (No more prospect for White to live in this corner.) ....................... *`Thick'*: A clear sure move that kills with- out question, no remain- ing eye space and no meaningful cutting points thereafter. ENDCOM W 106 q14 MARK \t@r13 \t@n15 \t@p15 \t@p16 \s@p16 \s@p15 \s@n15 COM W106 A forcing move which helps the three marked White stones and assures a connection with the White group below. It is Sente. ...................... Note: B106 threatens to cut off the marked Black stone from the group above. ENDCOM B 107 r14 MARK \t@r13 COM B107 Black connects to assure upper right territory and save the marked \t stone. ENDCOM W 108 l5 MARK \t@k5 \t@k4 COM W108 Another Sente move. ...................... Note: This move reduces Black's potential ter- ritory and threatens to atari the two marked black stones. So Black is obliged to reply. This move begins the "Endgame". Invasions, large territory posibil- ities, cutting attacks, etc. are all in the past. Every seemingly dead group can connect to one that is alive. ENDCOM B 109 l4 MARK A@k3 COM B109 This move is necessary. Black was short of liberties here and needed to protect the cutting point at A. ENDCOM W 110 b7 COM W110 The best end-game move on the board. ................... Note: Without #110 Black could slide down into White's lower left corner. ENDCOM B 111 g2 COM B111 The biggest end- game move which now remains on the board. ..................... Note: White must now respond or Black will keep pushing on into White's lower left corner area. ENDCOM W 112 f2 COM W112 White blocks Black's threat to push into White's corner territory. ENDCOM B 113 h2 COM B113 Black connects. ..................... Note: Black is well ahead in territory at this point. A strong player would be quite aware of this by now and he would resign. Black's territory at the top, bottom, and sides is about: -= 70 White's territory, lower left, center and on the right: -= 50 (The center is just an open area and there is no meaningful territory to be had there.) ENDCOM