(;FF[4]
CA[UTF-8]
GM[1]
GN[Becoming 9 Kyu - Lesson 24]
PC[https://online-go.com/review/413077]
PB[Black]
PW[White]
BR[2d]
WR[2d]
OT[Error: time control missing]
RE[?]
SZ[19]
KM[6.5]
RU[Japanese]

(;B[qd]
;W[pj]
;B[oc]
;W[qe]
;B[pe]
;W[qf]
;B[pf]
;W[rd]
;B[qg]
;W[rg]
;B[qh]
;W[rh]
;B[qi]
;W[rj]
;B[ri]
;W[si]
;B[qc]
;W[qj]
;B[oh]C[Hi! Let's investigate tactics on the first line. I imagine you've found yourself in trouble because of shortage of liberties before. I hope you can identify first-line tactics so you don't get trapped in a liberty shortage after this lesson!

-- chat --
debilbao40: Hello
asnark: hi!
lucasfrodopassos: hi
barsegott: Hi
Natacha_Go: Hello everyone
mark5000: This is a text-based lecture about tesuji.
TU3SDAY: Hi
mark5000: Yes, more or less. I start between 8 and 9 am PST. Today I slept in late and started at 9am. :|
deterdettol: Sweet :)
Natacha_Go: Yes lillou
YUI CHIT: Thanks Mark 🙏🙏🙏🙏🙏
]
(;W[sj]C[

-- chat --
47edde74bcd4496d: hi
]
)(;W[rc]C[Pushing here is an endgame play.

-- chat --
lillou: hi
]
(;B[rb]
;W[sb]
;B[qb]
;W[dp]C[White, however, tenukies here. What will the consequences be? White's moves here will result in a liberty shortage. Black has a good tesuji to punish White.]
;B[re]C[Cutting here is a good start.]
;W[rf]C[After White connects,

-- chat --
deterdettol: Helllllllllllllo
snakesss: https://www.youtube.com/watch?v=quEN6FE90bM
deterdettol: I lost the game
]
;B[se]C[This descent is part of a great combination.]
;W[sf]LB[sd:A]C[Since White can't atari at A, White needs to play here to capture the two black stones. What can Black do now?

-- chat --
lillou: nice ;)
lillou: t12
]
;B[sh]C[This throw in is a nice tesuji! Because of the snapback, White can't capture this stone.

-- chat --
Assai: t12
deterdettol: Isn't this shape called golden chicken standing on one leg?
deterdettol: 金鸡独立?
snakesss: "there will be a throwin tesuji"
mark5000: I'm not sure of the Chinese name, actually.
deterdettol: https://senseis.xmp.net/?GoldenChickenStandingOnOneLeg
]
;W[sd]C[Instead, White can only capture the two stones.]
;B[sj]C[But what if Black captures this white stone? The entire group dies. T17 is a false eye. The entire group dies. It's a false eye. Of course this result is disastrous for White.

-- chat --
snakesss: rip w
lillou: only one eye
snakesss: haxxx
]
)(;AE[rc]C[Going back to the original variation, White has no weaknesses at the moment.]
;AW[rc]C[This endgame move was the main cause of White's liberty shortage.]
;B[rb]C[As we saw, the consequences were dire. Let's look at another first line tesuji.]
)))(;B[pd]
;W[nd]
;B[lc]
;W[mb]
;B[lb]
;W[pc]
;B[oc]
;W[od]
;B[qc]
;W[pb]
;B[qd]
;W[pe]
;B[oe]
;W[qe]
;B[of]
;W[re]
;B[qb]
;W[qg]
;B[nb]
;W[mc]
;B[ma]
;W[rd]
;B[nc]
;W[md]
;B[le]C[Black plays here to capture White's group in a net. Is this group supposed to die?]
;W[rb]C[This attachment is just an endgame move.]
(;B[pa]C[Some players would choose to play this way. By exploiting White's weaknesses, however, Black can rescue the whole group.]
)(;AE[rb]C[What's the move?

-- chat --
scotto: m16
Natacha_Go: I miscalculated ;)
FeoDoT: O19
mark5000: :)
mark5000: Let's see it again.
mark5000: This tesuji is practical and useful
]
(;AW[ld]C[This push only reduces liberties. It's not the answer.]
;B[kd]C[

-- chat --
mark5000: Then what?
Natacha_Go: R19 ?
]
)(;AW[qa]C[This move is conceivable.]
;B[ra]C[Black would answer here on the first line. White can't connect due to shortage of liberties, so White has to make a ko.

-- chat --
snakesss: p19 perhaps
]
;W[oa]
;B[pa]C[This also isn't the best answer.]
)(;AW[na]C[This move looks tesuji-ish, but it goes nowhere.

-- chat --
lillou: it's done^^
]
;B[oa]C[

-- chat --
Natacha_Go: Yes O19 seems interesting
mark5000: What next?
Natacha_Go: hmm... still the same problem
]
)(;B[lm]
;W[pa]C[

-- chat --
snakesss: just descend then
]
)(;AW[pa]C[Descending is another move you can consider.

-- chat --
snakesss: yup this
snakesss: only one left basically xD
]
;B[oa]C[Black can resist here, however.WBlack can resist here, however.

-- chat --
June144: P19
]
)(;AW[oa]C[First of all, White needs to diagonal on the first line, like this. Now White can't avoid a liberty shortage.

-- chat --
mark5000: In this case, the diagonal on the first line is good.
]
;B[na]C[Black has no choice but to connect here.

-- chat --
Natacha_Go: I presume the idea is to minimize the possibilities of ko answers
]
(;W[rb]C[After that, White attaches here. The previous exchange is working well! Black can't play P18 because of a liberty shortage.

-- chat --
mark5000: Remember this combination!
mark5000: I've never heard a proverb like "There's a tesuji on the first line."
mark5000: In my opinion, however, it could be added as a new proberb.
Natacha_Go: =)
mark5000: I hope you'll be able to use this knowledge and look for first-line tesujis in your own games.
Natacha_Go: Thx a lot !
mark5000: That's all I had planned for today's lecture. Any questions?
lillou: thanks
Natacha_Go: Well... not exactly the subject but...
snakesss: lets see if we see lots of 25kyu games with random first line tesujis xD
Natacha_Go: here you can kill will S17 or R19
snakesss: first line moves are like broken clocks, they are correct twice a day
Natacha_Go: what is the best move to limit the possibilites of ko
Natacha_Go: ?
Natacha_Go: I'l not sur to be clear
mark5000: Where do you see a ko?
mark5000: And snakesss, the trick is to see when there is a tesuji and when there is not.
snakesss: both atariing moves for black would be selfataris
snakesss: not for white though
mark5000: Correct.
snakesss: cuz after m19, they can atari with o19
snakesss: without selfatariing
mark5000: Living is much cleaner than ko, even if you are the ko master.
snakesss: next: ko? mark? :)
mark5000: No, Not at all. Winning a ko just means your opponent's free move wasn't as big as the ko.
mark5000: Your opponent still got a free move, however.
mark5000: It's better to live and not allow any free moves.
Natacha_Go: Well, here maybe it is not a good example.
mark5000: If you grant your opponent two free moves in a game, there's one stone handicap right there. It's the difference between 10k and 9k.
Natacha_Go: What I try to say is...
snakesss: who interesting way of putting it
snakesss: whoa*
Natacha_Go: when I have different possibilities to kill a group sometimes I have a doubt in the choice
snakesss: i would love a lecture on ko
mark5000: Sounds good. Making ko will be next week's lecture.
Natacha_Go: OK. next time I'll try to prepare something
mark5000: Great.
mark5000: This lecture was part of my Saturday lecture series on becoming 9 kyu.
mark5000: Find past lectures here: https://forums.online-go.com/t/becoming-9-kyu-a-series-for-beginners/3809
mark5000: You're welcome.
snakesss: hahah maybe link your patreon mark? xD
mark5000: Ha, there's a donation link on my profile if you want to tip me!
mark5000: Thank you.
mark5000: lol
snakesss: lol
snakesss: thanks for the lecture!
mark5000: See you all the next time.
FeoDoT: thanks, Mark!
]
(;B[la]C[Therefore, Black needs to connect here first.]
;W[rc]C[Then White can capture four black stones. White saved the five stones beautifully.

-- chat --
lillou: :)
]
)(;B[ra]
;W[rc]
;B[qa]
;W[sa]
;B[sb]
;W[sc]
;B[sa]
;W[pa]C[

-- chat --
deterdettol: Yes:
deterdettol: Actually no, oops
deterdettol: Thank you!
]
)(;B[qa]C[

-- chat --
FeoDoT: if the Black stretches?. From move 0: Q16 O16 M17 N18 M18 Q17 P17 P16 R17 Q18 R16 Q15 P15 R15 P14 S15 R18 R13 O18 N17 N19 S16 O17 N16 M15 S18 S18 P19 O19 S18 R19 
Natacha_Go: I don' see any ko. I'm mean if afterwards there is a lko in the game
]
(;W[rc]C[

-- chat --
mark5000: Just connect here, I think.
mark5000: There's a liberty shortage here, too.
]
;B[ra]
(;W[dp]
;B[me]
;W[sa]
;B[sb]
;W[sc]
;B[ne]
;W[sa]C[

-- chat --
lillou: do you mean this?. From move 0: Q16 O16 M17 N18 M18 Q17 P17 P16 R17 Q18 R16 Q15 P15 R15 P14 S15 R18 R13 O18 N17 N19 S16 O17 N16 M15 S18 S18 P19 O19 S18 R19 S17 S19 D4 N15 T19 T18 T17 O15 T19 
]
;B[ld]C[?

-- chat --
Natacha_Go: to not give another move if some ko occurs afterwards in the game
mark5000: Feel free to construct a position that describes what your question is about.
]
;W[od]
;B[nd]C[

-- chat --
deterdettol: I learn more from your lectures than paying $18 for a lesson at my association 
deterdettol: Thank you OGS
deterdettol: Thank you mark5000
deterdettol: Also doesn't help my 4d teacher teaches in Chinese so I understand nothing but anyway
deterdettol: Thanks all
deterdettol: Cya at the next lecture!
deterdettol: Is the lecture same time same day?
]
)(;W[sa]
;B[sb]
;W[sc]
;B[me]
;W[sa]C[

-- chat --
lillou: natacha?
lillou: stillhere?
lillou: thanks mark see ya
lillou: goes to ko. From move 0: Q16 O16 M17 N18 M18 Q17 P17 P16 R17 Q18 R16 Q15 P15 R15 P14 S15 R18 R13 O18 N17 N19 S16 O17 N16 M15 S18 S18 P19 O19 S18 R19 S17 S19 T19 T18 T17 N15 T19 
]
)(;W[sb]C[

-- chat --
mark5000: You missed this.
mark5000: Same liberty shortage.
]
;B[me]
;W[sa]
;B[ne]
;W[pa]C[

-- chat --
lillou: yeah
lillou: i found it after thinking about this again
lillou: but with the other variation black got one moves less on the outside?
lillou: nono
lillou: just because in my variation black did take away one liberty of his own 
]
))(;W[ra]C[

-- chat --
lillou: seems clean. From move 0: Q16 O16 M17 N18 M18 Q17 P17 P16 R17 Q18 R16 Q15 P15 R15 P14 S15 R18 R13 O18 N17 N19 S16 O17 N16 M15 S18 S18 P19 O19 S18 R19 S19 
]
)))(;W[qa]C[

-- chat --
snakesss: when they do m19, yo gotta take a liberty
lillou: you were asking which move is better to capture after the attachment and black going to the first line weren't you
]
;B[ra]
;W[rb]C[

-- chat --
deterdettol: IF Natacha suggests wR19,
deterdettol: Then this is a ko?. From move 0: Q16 O16 M17 N18 M18 Q17 P17 P16 R17 Q18 R16 Q15 P15 R15 P14 S15 R18 R13 O18 N17 N19 S16 O17 N16 M15 S18 S18 P19 O19 R19 S19 S18 
deterdettol: But aren't ko fights good? If you can win?
deterdettol: Ah...
deterdettol: mark5000: I'll make sure to remember that exact line...
deterdettol: +1
]
;B[pa]
;W[rc]
;B[ob]C[

-- chat --
FeoDoT: if continue like this. From move 0: Q16 O16 M17 N18 M18 Q17 P17 P16 R17 Q18 R16 Q15 P15 R15 P14 S15 R18 R13 O18 N17 N19 S16 O17 N16 M15 S18 S18 P19 O19 R19 S19 S18 Q19 S17 P18 
]
))(;AW[ob]C[This atari is a bad move.]
;B[na]C[After Black connects, White has no follow up.]
))))