(;GM[1]FF[4]CA[UTF-8]AP[CGoban:3]ST[2]
RU[Japanese]SZ[19]KM[0.00]
PW[Baduk]PB[Movies]
;B[pd]
(;AB[jd]
;W[qc]C[Today we continue where we left off last time. We will show some more san-san sequences.]
;B[pc]
;W[qd]C[Last week we showed variations starting with the black hane at 1. 
Black can also play 2 to gain sente, or 3 to put pressure on the white group from the upper side. ]
(;B[qe])
(;B[qf]C[A move that aims at taking sente. 
]
;W[rf]C[Black can play tenuki or go for the right side.



]
(;B[dp]
;W[qg]
;B[pf]
;W[rh]C[White makes a very solid shape and takes territory on the right side. 
However, black gets the chance to play tenuki once again.])
(;AB[pj]SQ[pj]C[If black already has a stone at the marked starpoint..]
;B[qg]C[This extension is a good option.

White has two ways of answering, both leave black with sente.]
(;W[pb]
;B[ob]
;W[qb]
;B[pe]
;W[rg]C[Black can play tenuki. ])
(;W[qe]
;B[pe]
;W[rg]C[White usually finishes the sequence by pushing here.
Black can play tenuki.]))
(;B[rg]C[Good if the right side is important. ]
;W[re]
;B[qg]
;W[pb]
;B[ob]
;W[qb]
;B[nc]C[Black seals off both sides, but ends with gote. 
This position is very similiar to the most basic san-san variation, that we showed last week. 
To compare, let's see that position again.]
;AB[dd]
;W[cc]
;B[dc]
;W[cd]
;B[ce]
;W[be]
;B[cf]
;W[bf]
;B[cg]
;W[db]
;B[eb]
;W[cb]
;B[fc]LB[pe:A]SQ[ce][rg]C[The marked stones are the only differences between the two positions. 
On the left the marked stone is used for strength and influence. 
On the right side the same stone is used to block on the right side: better for territory, but weaker towards the centre (weakness at A).]))
(;B[qb]LB[pi:A]C[Usually black plays this when he already has stones around the A area. 
For an example, see the game between Wang Haijun and Yu Bin in the bonus tab. 
]
;W[rb]
;B[pb]
;W[qf]))
(;AB[jc]LB[jc:B][jd:A]C[Before, we saw the variations with a high black stone at A. 
What happens if that stone is low, at B instead?]
;W[qc]C[Now if white invades in the corner, black can play severely.]
;B[pc]
;W[qd]
;B[qe]
;W[re]
;B[rf]
(;W[pb]
;B[ob]
(;W[oc]LB[jc:A]C[When the stone at A is low, the white cut does not work. ]
;B[od]C[A strong move. ]
(;W[qb]
;B[pf]LB[jc:B][oc:A]C[If white tries to run with his A stone, blacks B is perfectly positioned.]
;W[nc]
;B[nb]
;W[mc]
;B[mb]
;W[lc]C[.]
;B[lb]C[Great for black. ])
(;W[nc]C[Desperate. ]
;B[qb]
;W[qf]
;B[pe]
;W[rg]
;B[rd]
;W[sf]
;B[rc]C[Superb for black. ]))
(;W[qb]C[White can live, but the result is good for black. ]
;B[pe]
;W[rd]C[Good for black. ]))
(;W[qf]C[The correct move. ]
;B[pe]
;W[rg]
;B[rd]
;W[sf]
;B[rc]C[White sacrificed the corner, but gets a group on the right side in sente. ]))
(;B[qf]C[What about the san-san invasion when there are other stones even closer by?

]
(;W[qc]C[Only good when white has no other options locally. This leads to a ko. ]
;B[pc]
;W[qd]
;B[qe]
;W[pb]
;B[ob]
;W[rb]
;B[pa]
;W[qa]C[A classical example of ko. ])
(;W[pc])
(;W[pb])
(;W[ob]))
(;B[qg]C[Instead of the keima corner enclosure, the oogeima is also often played.
The oogeima leaves a bigger cornerspace to invade. Here an invasion on san-san will succeed unconditionally. ]
;W[qc]
;B[pc]
;W[qd]
(;B[qb]
(;W[qf]LB[rb:A]C[In this situation it is crucial to jump first and leave the hane at A for later! ]
;B[pf]
;W[pe]C[Joseki. ]
;B[oe]
;W[qe]
;B[pg]
;W[rb]
;B[pb]
;W[rg]
;B[rh]
;W[sf]
;B[ra]
;W[sb]
;B[qi]LB[od:B][ne:A][of:C]C[White makes a living group insides blacks territory, but black gains strength on the outside. 
Note that black still has weaknesses at A-C])
(;W[rb]C[A mistake. ]
;B[pb]
;W[qf]
;B[pf]
;W[pe]
;B[oe]
;W[qe]
;B[rg]LB[pb:B][pg:A]C[Instead of connecting soldily at A, like in the previous sequence, black can now descend.
White is in trouble. ]
;W[ra]
;B[og]
;W[rf]))
(;B[qe]
;W[re]
;B[rf]
;W[pe]
;B[qf]
;W[pb]
;B[ob]
;W[qb]
;B[nc]
;W[rd]
;B[oe]C[Next episode we will explore the white position in the corner: It is called the L + 2 group.
Thanks for watching, and see you next time! ])))
