(;FF[4]
CA[UTF-8]
GM[1]
GN[Becoming 9 Kyu - Lesson 44]
PC[https://online-go.com/review/445001]
PB[Black]
PW[White]
BR[2d]
WR[2d]
OT[Error: time control missing]
RE[?]
SZ[19]
KM[6.5]
RU[Japanese]
C[

-- chat --
windway: Nice! thank you
]
(;B[ce]
;W[dc]
;B[cj]
;W[de]
;B[df]
;W[cd]
;B[ee]
;W[dd]
;B[dg]
(;W[cf]C[Hi! We're going to focus on sacrifice strategy. Let's look at an example. White just cut here. Actually, this cut is an improper move.

-- chat --
prosody: Hi!
applebaps: hello~
chel: hi
mark5000: Hello
manfred.georg: hi
MoonyBird: hi
mark5000: This lesson is text-based. It's part of my lesson series https://forums.online-go.com/t/becoming-9-kyu-a-series-for-beginners/3809
mark5000: Normally these lessons are 3 hours earlier than now. But I've been too busy to keep the regular time recently.
mark5000: Thanks
]
)(;W[be]C[Instead, this atari is better.]
;AE[be]
;AW[cf]C[How should Black respond now?]
(;B[cg]C[If Black ataris,]
;W[be]C[White will capture this black stone.]
;AW[bg]C[Later on, White can bend here in sente. This choice is bad for Black.]
)(;B[be]C[In this case, Black should sacrifice one more stone, like this. When you have a stone on the third line, it's usually good to sacrifice one more stone. 

-- chat --
cleinias: hi
]
;W[bf]C[After White blocks,]
;B[bg]C[Black can attach here.]
;W[bd]
;B[cg]
;W[ae]C[By sacrificing these two stones, Black got a solid position in sente. If you remember this sacrifice strategy, you'll find it useful. Let's see another example.]
)))(;AB[qp]
;B[dp]
;W[jq]
;B[hq]
;W[cn]
;B[cp]
;W[ck]
;B[lq]
;W[jo]
;B[op]
;W[lo]
;B[ho]C[By using a sacrifice strategy, White can make shape. Now, the three lower stones are weak. How should White manage the group?

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mark5000: Any ideas? Sacrifice strategies?
spungy boby 123: n3
cleinias: O3
pfpirlet: L4 ?
matrimsaric: h4
Dietrichstein: L8
prosody: I would go for N3, threaten the cut and maybe it's a dream sequence but hope for the nice eyeshape with M4 and L3
snakesss: there is n2, but is it good right now?
Etyllr: hello im french sorry im débutante
snakesss: i doubt it
applebaps: why not cap with H6, then when black cuts, lean on the large knight's move to the right?
tpnZbonek: hello mark
mark5000: I'm excited to see so many great ideas!
tpnZbonek: L3 makes good shape and it is good for atack left or right
mark5000: Let's look at the wrong answers first.
spungy boby 123: n2 maybe
tpnZbonek: what about peep at Q3 and then attack stone at M3?
]
(;W[nq]C[

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Anthe: l3 is a good shape move ?!
mark5000: First, this "armpit" hit is close, but not quite right.
snakesss: lol pro
]
(;B[mp]
;W[np]
;B[mo]
;W[no]
;B[mn]C[

-- chat --
mark5000: Black could move out like this, and the three stones got weaker.
tpnZbonek: ok sorry i can see the topic of this lesson is something else..
]
)(;B[np]
;W[mq]
;B[mp]
;W[lp]
;B[lr]C[

-- chat --
mark5000: Besides that, just covering works, since Black has more liberties and will win a capture race
snakesss: if you want a table shape, n3 might induce it
snakesss: no need to bump
]
))(;W[kp]C[

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mark5000: This move fixes the weaknesses. It's also crude and ugly looking.
mark5000: Try to avoid moves that do only one thing.
prosody: you can be kikashi'd into a B2 bomber too
mark5000: Yes, it's not a good shape. It's corruptible.
]
)(;W[hp]C[

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mark5000: This wedge is interesting at first glance.
]
;B[gp]
;W[ip]C[

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mark5000: But if Black just ataris, White just gave up sente without improving the shape.
mark5000: Be careful about this.
]
)(;W[kl]C[

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mark5000: This jump is the best suggestion yet.
mark5000: It moves into the center and improves the shape.
mark5000: But it's still not best, and it's not a sacrifice strategy we're looking for
BluesBells: O5?
]
)(;W[hn]C[

-- chat --
Archelao5: J6?
windway: M2?
TagataSan: m2?
mark5000: This attachment is also a good idea, but not right for the same reasons.
]
;B[gn]
;W[in]
;B[gm]C[

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mark5000: Black gets stronger, and White didn't improve the shape much.
applebaps: hm! interesting
prosody: sacrifice the three stones and take one of the top corners
tpnZbonek: :d 
mark5000: Making shape is not easy sometimes.
]
)(;W[no]
;B[np]C[

-- chat --
tpnZbonek: well if we want just make a good shape i suggest L3 but seems slow to me in this situation
mark5000: O5 helps Black secure territory.
mark5000: But actually it benefits White too. Still not best.
]
)(;W[mq]C[This attachment is a sharp and good move.This attachment is a good sharp and good move. ]
;B[mp]C[But you need to know follow ups after Black bends here.

-- chat --
xhu98: came in right before the ultimate tesuji :)
]
;W[lp]C[First of all, cutting here is important.]
;B[nq]C[Then Black will atari.]
(;W[kq]C[If White ataris,]
;B[mr]C[Black will capture this white stone. It's no good.

-- chat --
mark5000: :)
]
)(;W[mo]C[And if White ataris here,]
;B[mr]C[Black will again capture this white stone. It, too, is no good.

-- chat --
mark5000: If players rated 10k+ find the N3 move, they will always stop reading here.
mark5000: That makes me sad.
mark5000: You will conclude that N3 is bad, and then you'll play L8 or O5 or something like that.
matrimsaric: drop to n2 then black drops to l2 and white can fill l3?
]
)(;W[mr]C[So you should sacrifice one more stone when there's a stone on the third line.

-- chat --
prosody: white n2 black m2 white l2
]
;B[lr]C[After Black blocks,]
;W[mo]C[This atari is a good forcing move.]
;B[np]
(;W[kq]C[Then White can bump here. This is a mouth shape--a classic good shape. Initially, the white group was weak. But now this group is thick! The lower right corner is big, but it was already Black's territory. Let's look at one more tactic!

-- chat --
matrimsaric: nice
]
)(;W[kr]C[Or attach here.]
))))(;B[pd]
;W[qd]
;B[qc]
;W[pe]
;B[od]
;W[qe]
;B[rc]
;W[qg]
;B[rd]
;W[oe]
;B[re]
;W[rf]
(;AW[nd]C[White struck at the head of Black's two stones. You shouldn't let your opponent play such a great move.]
)(;B[nd]C[If possible, you should stretch here first.]
;AE[nd]C[

-- chat --
kissmecomix: 1. From move 0: Q16 R16 R17 Q15 P16 R15 S17 R13 S16 P15 S15 S14 O16 O16 
kissmecomix: q18 is beter
]
;W[nd]C[But Black had to play elsewhere, since there was another urgent point to play. So White played here. How should Black answer now?

-- chat --
Aselan: P18
Dietrichstein: O15
mark5000: Black to make shape. Assume Black isn't strong enough to cut.
cleinias: o17
MoonyBird: 015?
nieutseucheu: q18
BluesBells: What speaks against O17
applebaps: B O17, W P17, B Q17, P18, B Q18?
Legault: tenuki, black is alive locally
Legault: :^)
mark5000: Last time a 2k found the answer immediately. I imagine our 2k+ spectators have found the move, here too ;)
mark5000: But this lesson is for 10k+ players >_>
xaphan2019: P19
xaphan2019: i mean 18
Aselan: Puh
Aselan: Good
Aselan: I had p18
igsNomad: That is why we stay silent =^.^=
Aselan: P19 would have shocked me
Legault: If black tenukis the o17 wedge, is the fiercest move for white q18 wedge?
Kawabata: o18? isn't it better?
mark5000: In this case, there's a sharp move. And only one player found it.
xaphan2019: was the same result safly
xaphan2019: he just showed
Counting Zenist: https://online-go.com/demo/view/445012
Counting Zenist: I made a global position for the lesson that could be played/forked as a normal game, hope it would help
]
(;B[ll]C[

-- chat --
tpnZbonek: if you Q18 white will P17 and poke eye.. 
tpnZbonek: O18
]
;W[nb]
;B[oc]
;W[ob]
;B[pc]
;W[pb]C[

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tpnZbonek: 2. From move 0: Q16 R16 R17 Q15 P16 R15 S17 R13 S16 P15 S15 S14 O16 O16 O16 M8 O18 P17 P18 Q17 Q18 
tpnZbonek: you can keep continue to the left side territory like this
kissmecomix: o17i s too far to help
Aselan: I dont get it can you show aboce?
]
)(;B[nc]C[If Black plays here,

-- chat --
McStrauss: why not O17?
xaphan2019: every variation of 017 will enclose black by the looks of it
xaphan2019: double hane would create more aji for white, may not be much, but if it stays until end game; it could result in ko threats and point deduction later on
xaphan2019: i think the pint Mark is trying to make here, is that why create problems in shape?
]
;W[mc]C[White will double bend. This move is painful for Black.

-- chat --
xaphan2019: 017 ruins influence and keeps you enclosed
]
(;B[nb]C[Some players stretch in this kind of situation. But that's the worst response.

-- chat --
applebaps: Why not just N16 after the double hane?
]
;W[mb]C[If White blocks here,]
(;B[pb]C[Black still has to respond like this.]
;W[md]C[After connecting here,]
;AW[na]C[White can bend here in sente as well.

-- chat --
matrimsaric: i suppose white can use p18 to firce black ingo alob
matrimsaric: ta for the lesson
]
)(;B[oc]C[Even if Black connects here,]
;W[md]
;AW[na]C[This bend is still sente. Because of that, it's the worst variation for Black.

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kissmecomix: that is why q18 is good you make shape
]
))(;B[md]C[

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tpnZbonek: thats why i am into O18 -_-
mark5000: applebaps asked why not here after the double hane
]
;W[ne]C[

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kissmecomix: 3. From move 0: Q16 R16 R17 Q15 P16 R15 S17 R13 S16 P15 S15 S14 O16 O16 O16 O17 N17 N16 O15 
kissmecomix: what is keeping white from taking the 2 stones?
]
(;B[nb]C[

-- chat --
mark5000: It doesn't really change anything
mark5000: White will still play out the same variation, and Black is caught in a ladder.
applebaps: i was thinking of an atari after W connects, rather than an extension
tpnZbonek: for W sharp move?
]
)(;B[mb]C[

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applebaps: like, say, N18 or M17
applebaps: break through to the side
tpnZbonek: he can double atari then
]
;W[oc]C[

-- chat --
mark5000: ???
mark5000: Brave to give White this
snakesss: huh, i thought cut and extend was almost always good after doublehane
]
)(;B[lc]
;W[oc]C[

-- chat --
mark5000: Black would collapse
Kawabata: Hello nice people
applebaps: i see
]
))(;B[ob]C[Instead, tiger's mouth is a better move.

-- chat --
tpnZbonek: i was tellin M18 by i meant O18 -_-
xaphan2019: i feel like im a much smarter go player when watching than playing lol
]
;W[nb]
;B[oc]
;W[md]C[Then White will defend this weakness after exchanging the atari. But as you can see, Black's shape doesn't look so nice. It's an unsatisfactory result for Black.

-- chat --
xaphan2019: this still ultimately encloses black though, yes?
mark5000: Yes
Legault: As in, black doesn't play the wedge
applebaps: thank you for the lesson and your time!  i do have a question: is there a simple way to think about the valuation of a sacrifice play or to know when one is necessary versus a more fundamental strategy?  i.e. when is it better to aim for shape directly versus throwing away stones?
applebaps: or does it all just come down to reading
konradiking78: thanks
mark5000: This is a locally settled position.
Legault: Yes, I realise that
Legault: I mean if black does not play the o17 wedge
]
))(;B[ob]C[Many of you thought about this jump as well.

-- chat --
xaphan2019: yeah, i get it Mark; XD
]
;W[nb]C[But White will attach here,

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mark5000: Oh, this
Legault: Yes
]
(;B[nc]C[Then Black has to wedge and connect.

-- chat --
xaphan2019: yeah
]
;W[mc]
;B[oc]C[Like this. It's the same as the previous variation, and it isn't good.

-- chat --
Dietrichstein: This is all defense, maybe immediately go on the attack O15?
applebaps: he'd said assume B isn't strong enough to cut
Aselan: Cool
xaphan2019: thanks
Legault: If black tenukis, is the strongest attack by white q18?
]
)(;AW[nc]C[

-- chat --
mark5000: I'd play where I think that Black should have played.
xaphan2019: yeah this just looks bad
Legault: Hm. Black should play q18 now then?
mark5000: White is so strong
applebaps: now black has no way out whatsoever
Legault: Sack the p16 stones for life?
applebaps: the wedge creates a 2nd line W stone that can be taken later
mark5000: Yeah, it's just bad.
xaphan2019: Q18 is probably the best
applebaps: tiny sad life
]
;B[pb]
;W[oc]C[

-- chat --
xaphan2019: b q18 w 017
xaphan2019: then ur forced into l/d
]
))(;B[nb]C[This knight's move is the answer. 

-- chat --
xaphan2019: oh, i thought u said p18 my bad lol
]
(;W[nc]C[If White bumps,]
;B[ob]C[Black stretches here. Black can easily connect up without any problems.]
)(;AB[ne]C[If White plays elsewhere, Black can cut, if Black is strong enough for cutting.

-- chat --
xaphan2019: love this shape XD
xaphan2019: that stone can only run one way now
]
)(;AB[lc]C[Or Black can fly out here. So Black can still develop territory at the top.

-- chat --
Dietrichstein: shine!
]
)(;W[mb]C[This attachment is the strongest move for White. Now Black needs to answer carefully.

-- chat --
tpnZbonek: ah ok
xaphan2019: so why must black play 018 after the n18 attachment?
mark5000: Somebody asked why Black has to respond at all here.
mark5000: First, responding is sente. White answers, and it helps your position, so it must be worthwhile.
]
(;B[nc]C[If Black bumps like this,]
;W[mc]C[It'll be the same as the worst variation that we saw before. So Black must not play like this.

-- chat --
prosody: that it's black's turn mostly
]
)(;B[mc]C[This inside bend is an overplay.]
(;W[nc]C[White will cut here. Black has many weaknesses now.

-- chat --
snakesss: you should show what happens if white atari and connect, since this is ddk-aimed
]
)(;AE[mc]
(;AB[ob]C[So this stretch is the best response for Black.

-- chat --
Dietrichstein: thanks
]
;W[mc]C[After White connects up, Black can play elsewhere.

The focus of today's tactics was on getting a good position, through sacrifice and thinking about shape. I hope you'll find them useful!

-- chat --
Kawabata: Is cut available now?
tpnZbonek: kawabata i guess if B is stron on the top left, otherwise its unreasonable
Kawabata: Ok ty
tpnZbonek: thanks mark
mark5000: Any questions? I saw a lot of discussion here.
Legault: Yes
Kawabata: Thanks for the lesson
xaphan2019: something happened to the lecture and ibecame lost on how black needed to play p18 after the connnection to n18
Legault: In the position, where black has the o17 wedge
prosody: thank you!
Aselan: Ty
mark5000: Someone asked how you can know when to look for sacrificial tactics
applebaps: yeah!
mark5000: First, you can look for them when you have a single stone in atari on the third line.
mark5000: We saw this in examples 1 and 2.
mark5000: Second, you can look for them whenever you have a weak group that needs to make shape.
applebaps: ah! neat, yeah that's pretty easy to remember
mark5000: As in example 2 (and 3, to a lesser extent)
]
)(;AW[ob]C[

-- chat --
mark5000: Second, this move (again taking your opponent's good move) is cruel
applebaps: oof yeah
mark5000: Black has no good reply
mark5000: Other questions about sacrificial tactics or related stuff? Did I miss any?
mark5000: Thanks to everyone here! Find past lectures at https://forums.online-go.com/t/becoming-9-kyu-a-series-for-beginners/3809
]
))))(;W[pc]
;B[oc]C[

-- chat --
cleinias: Thanks Mark! Mostly over my head but I still learned a lot. And it was fun
]
)))))