(;FF[4]
CA[UTF-8]
GM[1]
GN[Becoming SDK - Lesson 1]
PC[https://online-go.com/review/54051]
PB[Black]
PW[White]
BR[1d]
WR[1d]
OT[Error: time control missing]
RE[?]
SZ[19]
KM[6.5]
RU[Japanese]
LB[qc:B]LB[pd:A]LB[qd:C]LB[pe:D]LB[qe:E]
(;B[pd]C[The 4-4 point is on the fourth line. It focuses more on influence than territory.]
(;W[qc]LB[pc:B]LB[qd:A]C[What if White invades? Then Black should block on one side or the other.]
;B[qd]C[This starts a joseki. This is the most basic joseki when White invades at 3-3. If you don't know this joseki yet, I recommend that you learn it now. ]
;W[pc]
;B[od]
;W[nb]LB[pj:A]C[The moves up to here complete the joseki. Even though Black played first in the corner, White got territory on the inside. Is it bad for Black then? No it isn't. In exchange for the territory in the corner, Black gained influence on the outside.

Now you need to understand the concept of influence. Territory is like cash, whereas influence is more of an investment. The value of the influence all depends on how Black manages it in the future.

Here, Black can expand the framework at the right. If a fight breaks out, this influence will become effective. Black also has sente (sen-tay)—the freedom to play anywhere next. So extending to A can be a good choice in some cases. The box-like structure that results may become territory later. But for now it's only an investment.]
)(;W[qf]LB[qd:A]LB[rd:B]C[When Black plays a 4-4 point, White's approach with the knight's move is the expected response. It threatens to encroach into Black's corner by attaching at A or sliding at B. It's a powerful move.]
;AW[nc]C[If White can approach both sides at once, Black's corner weakens even more. If you can get this position in one of your games, it's usually a good idea to take it.]
))(;B[qc]C[Unlike the 4-4 point, the 3-3 point is territory-oriented.]
;W[pd]LB[pc:B]LB[qd:A]C[If White plays here, Black can push on either side.]
;B[qd]
;W[pe]
;B[ob]C[This is the most basic joseki. ]
;W[qe]C[Up to here it's a simple joseki. Black successfully secured the corner as planned and also the upper side area. Black, however, gave White control of the center and the right side area. Is it a bad result for Black then? No, Black took the corner as planned, so it's okay.

If you love territory the 3-3 point is a good option for you. We still have 3-4, 5-4, and 3-5 points to consider. They follow similar principles.]
)(;B[qd]C[What are the merits of the 3-4 point?]
(;AB[oc]C[If Black encloses like this, Black can secure the corner with just two moves. This position is called an "enclosure." What would a 4-4 point enclosure look like?]
;AE[oc]
;AE[qd]
(;AB[pd]
;AB[nc]C[Unlike with the 3-4 point enclosure, the corner isn't completely secure in this case. ]
;W[re]TR[qc]C[White can submarine into the corner later, like this. And the 3-3 point is still open too. Because of that, it's hard to say that the corner is complete.]
)(;AB[qc]
;AB[od]C[From the 3-3 point, this knight's move forms an enclosure, too. How about this?]
;W[mc]C[This approach is a bit irritating for Black. Compared to the 3-4 point enclosure, this one is certainly less secure.]
))(;W[od]C[After White approaches a 3-4 point, both sides need to fight for the space on the upper side.]
;B[oc]C[Attaching here is the simplest response to White's approach. Black will take territory in the corner, and White will get strong on the upper side.]
;W[nc]
;B[pc]
;W[nd]
;B[qf]
;W[jd]C[This is a simple joseki for the 3-4 point.]
))(;B[pe]LB[pc:A]LB[qc:B]C[This move is similar to the 3-4 point josekis. It aims for influence instead of territory. White may invade at A or B.]
)(;B[qe]C[This 3-5 point is one point outwards from the 3-4 point. It is the most aggressive of the popular opening moves, but it doesn't secure very much of the corner.]
;W[pc]C[It's common for White to take the enclosure point, because Black wants it to seal the corner.]
))