(;FF[4]
CA[UTF-8]
GM[1]
GN[Becoming 9 Kyu - Lesson 35]
PC[https://online-go.com/review/429881]
PB[Black]
PW[White]
BR[2d]
WR[2d]
OT[Error: time control missing]
RE[?]
SZ[19]
KM[6.5]
RU[Japanese]

(;B[qd]
;W[dc]
;B[cp]
;W[qp]
;B[eq]
;W[de]
;B[oc]
;W[oq]C[Hi! Let's look at how and where to best extend along the side. Here's an example. It's Black's turn to play.

-- chat --
marianadi.mincu: hi all
HamOfTruth: Hello
Daimo: 👋🏼
mark5000: You're welcome!
mark5000: Thanks for watching
mark5000: Remember the two principles of extending!
Binikumontoksusunya: thanks mark
marianadi.mincu: thx
Muzungu: thank you !
orplus: thank you
mark5000: Find past lectures here: https://forums.online-go.com/t/becoming-9-kyu-a-series-for-beginners/3809
]
(;B[qg]C[Black played a two-space extension

-- chat --
jillgoodgal: this is a good situation for a question, what best now, move into center right, or extend out on the bottom?
]
;W[cj]C[Then White made a wide extension here.]
;B[qj]C[Black extended again like this.]
;W[jc]C[White made another wide extension.]
;B[qm]LB[cm:C]LB[cn:B]LB[co:A]C[Black played here.

-- chat --
mark5000: Yes!
mark5000: ABC are all fine
jillgoodgal: from the final earlier position I meant
]
(;W[cn]C[And White approached.

-- chat --
mark5000: There was a question about this move
jillgoodgal: two weak black groups, only one weak white group
mark5000: So Black isn't well served by invading there now.
]
(;B[lc]C[Black extended again.]
;W[je]C[Then White jumped here. If this happens, which side has the better position? To state the conclusion first, it's better for White, of course. Some strong players would even say that Black's situation is hopeless. What was the main reason for Black's failure? Black's extensions weren't efficient enough. When enlarging your framework, you have to extend  widely. Black should have developed his area into a large framework, but these extensions were too tight.

-- chat --
Secretuse: I would agree i white would have stone at C7 instead o C6. As I see it, blak has no weakpoints, while white has several bad ajis.
Binikumontoksusunya: agreed with secretuse
jmdingess: Black is overconcentrated everywhere
Daimo: It’s a poor ratio of points to stones for black
mark5000: That's the thing: it's too easy to fall into this mindset thinking the tight extensions are ok. This kind of thinking, mistaking the bad for the good, is really frightening.
Secretuse: It is better to be safely overconcentrated, than having thinposition with bad aji.
mark5000: To improve, you have to understand why good is good.
Daimo: Do wide extensions result in lower total points because all territories are smaller?
Binikumontoksusunya: so what if i move black to say C13?
Secretuse: I find C6 to be overplay.
]
(;B[cg]C[If Black invades around here,]
(;W[dh]C[A modern strategy is to shoulder hit and attempt connection.

-- chat --
marianadi.mincu: live .
Binikumontoksusunya: what if white play C15 instead?
jillgoodgal: it seems the key is to learn how far to extend without creating two weak groups anywhere
jillgoodgal: C6 seems the only real white weakness right now?
jillgoodgal: no when you were discussing how far to push with black and black moved downwards
jillgoodgal: there was a large white moyo upper left
]
)(;W[ce]C[

-- chat --
marianadi.mincu: C16
mark5000: C15 is over-concentrated
marianadi.mincu: better
Daimo: And slow
]
)(;W[be]C[If you want to defend the corner, jumping down is fine.

-- chat --
mark5000: Right
Binikumontoksusunya: and if I respond to F13 for black?
mark5000: In this case, White has weaknesses, but White's play is also much more efficient than Black's
]
;B[fg]
(;W[ei]C[White can simply follow. Playing on this side helps reduce the weakness of White's big extension to C6.]
)(;W[ej]C[One-space jump is even more solid., .

-- chat --
Binikumontoksusunya: why not F11?
]
)(;W[fi]C[This is fine too.

-- chat --
jmdingess: choice of E10, E11, F11 is just how much you want to defent the aji of C8 later while attacking
jmdingess: but black is not accomplishing anything with C13 or F13
jmdingess: the stones dont to anything
mark5000: Perhaps. But Black has a weak group running for its life. Black can't take time out now to attack any weakness White has.
mark5000: In any case, I want to get back to efficiency.
]
)))(;AE[de]
;AW[ce]C[Imagine White had this small-knight's enclosure instead of the high enclosure.]
;B[cg]C[And Black invades here.]
;W[de]C[You'd never play this slow stretching move now. But it would become the same position. By flipping the order, you can often reveal moves that you thought to be good are actually not so good.

-- chat --
Binikumontoksusunya: i see
]
))(;B[cl]C[

-- chat --
mark5000: I suppose people worry about this invasion point
mark5000: Does anybody know how to make mischief here?
mark5000: There's a trick for leaning on the corner to build power for a counter attack.
VincentSalsero: C3 ?
Daimo: D7?
Shekomaru: E10?
Binikumontoksusunya: E10
marianadi.mincu: B8
orplus: b6
Binikumontoksusunya: E10 or E6
mark5000: E10 is good. But it's a sacrificial tactic. If you play it, it's fine. But I'm looking more at activating C6 right away
Shekomaru: B4?
Secretuse: I think, it is better to attak thsi position indiretly with C12 instead o C8.
mark5000: Ah, ok
Binikumontoksusunya: E4?
mark5000: I realize you're 3 kyu and above the level of this lecture, but it looks like there's enough interest
mark5000: Click sync.
Daimo: I like the drop by one 
]
(;W[en]C[First, just jumping up can be fine. Black can't link up easily. This would start a running battle.

-- chat --
jillgoodgal: the book suggests pressing down against the third line
]
)(;W[bp]C[The tactic I had in mind starts here.]
;B[bq]C[Black blocks.]
;W[dp]C[Then White can clamp here.]
;B[cq]C[Black should connect.]
(;W[en]C[And now White can jump here. Playing like this gains some extra white stones that can help if BLack struggles.

-- chat --
Binikumontoksusunya: why you dont move to C5?
mark5000: C5 is good too
]
)(;W[co]C[Playing here directly is also good.]
(;B[ep]C[If Black tries to enlarge the framework on the lower side, it would harm the C8 stone.]
;W[eo]
;B[fo]
;W[fn]
;B[go]
;W[gn]
;B[ho]
;W[ej]C[White would swallow black whole.]
)(;B[el]C[So Black can think of jumping out right away.]
;W[fo]C[White would probably jump out to keep the pressure on, and it's another running battle. But White is threatening to block off the lower side at around F3, so White can make a potentially huge territory on the lower side if Black isn't careful.

-- chat --
Binikumontoksusunya: i see
mark5000: One point about efficiency: it may not seem like an advantage at the time, but finding the right balance between loose and tight in the opening can pay off in territory later.
]
))))(;B[ch]C[This move was mentioned.

-- chat --
mark5000: So this invasion isn't too bad now.
mark5000: If you make large frameworks like this, it's worth learning tactics like this to convert it into profit later.
mark5000: And yes
mark5000: Black gained something. But White gained more.
mark5000: That's the spirit of Go
mark5000: Making small gains through the placement of stones, and those gains build up and turn into more points at scoring. Then you win.
Secretuse: I think, pushing one more extra move at G11 is not good, I would rather jump at F9
]
;W[eh]C[White can just cap it like this. Black won't have an easy life. Living on the left side would help White both fix the weaknesses in the large extensions and help White develop them into a large-scale framework.]
(;B[di]C[For example, if Black moves out,

-- chat --
jillgoodgal: but the start of a base maybe means black only needs one eye in the center instead of two
jillgoodgal: so I wondered, which is more key, the center right or the open lower part
]
;W[dk]
;B[ei]
;W[fh]
;B[fi]
;W[gh]
;B[gi]
;W[hh]C[White fixes the lower left weakness and converts the upper part into eighth line territory. It's a big win for White.]
)(;B[be]C[If on the other hand Black lives on the left,]
;W[cd]C[Black has little space to move about and may decide to move out anyway.]
;B[di]
;W[dk]
;B[ei]
;W[fh]
;B[fi]
;W[gh]
(;B[gi]
;W[hh]C[Black didn't gain much.]
)(;B[fk]C[

-- chat --
mark5000: You think?
]
;W[en]C[

-- chat --
mark5000: I'd be happy to jump up. It looks like White is still attacking Black.
]
(;B[hj]C[

-- chat --
mark5000: Black would need another move around here anyway
]
;W[ih]C[

-- chat --
Secretuse: I simply do not like pushin from behind unless it is really necessary
mark5000: THen White has a few choices, including here.
mark5000: Ok
mark5000: I hear that pushing from behind is bad surprisingly often.
jillgoodgal: Opening Theory Made Easy
mark5000: Oh, is it Hideo Otake's principle?
Secretuse: Also I would rather play G6 instead of H10
jillgoodgal: yes, along with extend at any cost
mark5000: That would make sense why I hear it so much
jillgoodgal: he would love your white extension
jillgoodgal: yes from here
mark5000: The upper side is the most important.
jillgoodgal: I would probably choose extension along the bottom, good thing I asked!
mark5000: White is building a huge framework there.
mark5000: Any other questions?
]
(;B[lc]C[

-- chat --
mark5000: As Black, it's worth reducing it any way you can. Now, while you still can.
jillgoodgal: thank you so much!
]
)(;B[kd]C[

-- chat --
mark5000: Shoulder hit is also nice.
mark5000: Go deeper at your peril
]
)(;B[je]
))(;B[gn]
;W[hj]
;B[gl]
;W[mc]C[

-- chat --
mark5000: Looks like we're playing a game now
mark5000: Yeah, this could happen. If you ask me, I'd happily take White.
Secretuse: I am sorry for interrupting. I did nto mean to play a game with you during lesson
mark5000: Does anyone have another question about extensions?
mark5000: And don't worry! I thought some people find this interesting. You have to know how to play after the opening too
mark5000: Here?
]
)))))(;W[cm]C[

-- chat --
mark5000: If the invasion doesn't work that well, then White needn't settle for just this one
mark5000: Although it's also fine.
]
)(;W[co]
;B[do]
;W[cn]
;B[bp]
;W[dn]
;B[eo]C[

-- chat --
mark5000: Modern players would probably attach like this.
mark5000: It's a third choice
]
))(;B[qj]C[When it comes to managing your group, a two-space extension is best. But this situation has nothing to do with settling Black's group. So this kind of wide extension is better. But this theory doesn't always apply. Let's see another example.]
))(;B[pd]
;W[pp]
;B[nq]
;W[qm]
;B[pq]
;W[qq]
;B[qp]
;W[qo]
;B[rp]
;W[oq]
;B[pr]
;W[op]
;B[or]
;W[rq]
;B[ro]
;W[rn]
;B[po]
;W[oo]
;B[qn]
;W[pn]
;B[rr]
;W[qo]
;B[qr]C[When your opponent's position is thick and powerful, you should extend solidly. Here's an example. Suppose White plays elsewhere and it's Black's turn to move on the right side. White has a solid position here. In this case, a wide extension isn't a good idea.]
(;AB[qj]C[What if Black extends all the way to here?

-- chat --
Daimo: Isn’t part of the problem that black has no corner enclosure to support a wide extension?
mark5000: Yes
marianadi.mincu: pincer R13
itsuone: R12 attack
Daimo: R12!
Binikumontoksusunya: attack it!
jillgoodgal: or even R14 approach
mark5000: You can think about it either way: Extensions are poor choices without enclosing first. And why is this so? Because you leave nice attacks for your opponent.
]
;W[qg]C[Since White has an iron wall in the lower right, White will invade around here immediately.]
;B[oj]C[Black can run away.]
;W[nh]C[But White will chase and attack the black group.an d attack the black group.

-- chat --
Binikumontoksusunya: follow it :3
jillgoodgal: so black should play something like R13 extension?
]
;B[mj]
;W[nc]C[As a result, White will take the initiative and gain an attack against the corner. So Black's extension was too greedy. There's a Go proverb: "Don't play close to thickness." When your opponent has an iron wall like this, you shouldn't be greedy. You negain  an attack against Blathe corner. So Black's extension was too greedy. There's a Go proverb: "Don't play close to thickness." When your opponent has an iron wall like this, you shouldn't be greedy. You need to extend carefully.

-- chat --
jillgoodgal: yes hit that corner!
jaden.hacking: thx for review
jillgoodgal: extend long on an empty board, extend more carefully towards thickness?
jillgoodgal: I would just kick as black then try to secure the corner
]
)(;AB[qg]C[In this case, the small knight's move or this long knight's move is appropriate. Because of White's powerful thickness, you should keep your distance. 

So we've learned two tips for choosing an extension. First, extend widely when enlarging your framework. Second, when your opponent's position is strong, your extension should be solid and tight. Because iof White's powerful thickness, you should keep your distance. 

So we've learned two tipes for choosing an extension. First, extend widely when enloarging your framework. Second, when your opponent's position is strong,   extend solidly annd tight.

-- chat --
Shekomaru: Thanks a lot Mark :)
mark5000: Does anyone want me to go back and explain the first principle more?
orplus: yes
mark5000: I'm happy to look at other patterns or answer any extension efficiency questions you have
jillgoodgal: sorry where are we at on the positions?
]
)))