(;GM[1]FF[4]CA[UTF-8]AP[CGoban:3]ST[2]
RU[Japanese]SZ[19]KM[0.00]
PW[Honinbo Dosaku]PB[Yasui Chitetsu]DT[1674]PC[Japan]SO[http://gobase.org/games/japan/misc/disks/dosaku/dosak14.sgf]US[Converted by sgf2misc-2.7.2]RE[W+5.00]
(;B[cp]C[Hi, last week we got a lot of positive comments about our episode, thank you all for that. And thanks for all the suggestions for new episodes you did send. In this episode we would like to talk about another great master: Honinbo Dosaku. He lived in the 17th century, about 200 years before Shusaku was born. ]
(;W[eq]C[Dosaku is white in this game.]
;B[hq]C[His opponent is Yasui Chitetsu 7dan.
This two space low pincer used to be very popular.]
;W[qo]
;B[qd]
;W[oc]C[Taking the empty corner would be the modern style. When Kim was in China he learned that approaching a corner like this is 2 points or so smaller than occupying the empty corner.]
;B[dc]
;W[ce]
(;B[mc]C[Dosaku was the inventor of many go techniques. He pioneered the tewari analysis.
Tewari is a technique in which you look at a position after it has been played and determine whether the stones are at the best possible places.
]
;W[md]C[Dosaku also was a pioneer in the concept of overconcentration. He often forced his opponent to play too many stones in one area. Maybe he was confident about applying over-concenteration because of his tewari abilities.]
;B[ld]
;W[ed]C[What follows is a great example of overconcentration]
;B[ec]
;W[fd]
;B[gc]
;W[gd]
;B[hc]
;W[fc]
;B[fb]
;W[gb]C[This kind of move is difficult to grasp at first glance, but good to think about.

]
;B[hb]C[Black simply takes the stone and you might think: didn't white just give his stone away for nothing?]
;W[eb]
;B[ga]
(;W[cc]C[But white gains a forcing move here.]
;B[db]C[Whites shape may seem thin and fragile, but black has no good moves available

]
(;W[qg]LB[hb:B][cc:A]C[So in what we just showed white exchanges his move at A for a black move at B.

Black gets an extremely strong shape. Why is this not bad for white?
Dosaku will show us in the next moves. 
]
;B[pe]
;W[nd]
(;B[of]C[Is this move necessary? Can't black think about defending his two stones at the top?]
;W[lc]C[Dosaku uses a sacrificing technique to make black overconcentrated]
;B[kc]
;W[lb]
(;B[kb]C[Yasui Chitetsu played here.]
;W[le]
;B[kd]C[As you can see black is heavily overconcentrated now.
Let's do a small tewari analysis to give you a better idea.


So now with that in mind, look at the positioning of black stones in the actual game. Black is forced to play 

So how could black have prevented all of this?]
(;W[qb]
;B[mf]
;W[qj]
;B[ph]
;W[qh]
;B[mb]
;W[rc]
(;B[op]
;W[pq]
;B[oq]
;W[pr]
;B[lq]
;W[cm]
;B[do]
;W[cj]
;B[fp]
;W[pi]
;B[on]
;W[or]
;B[nr]
;W[po]
;B[oo]
;W[cr]
;B[qc]
;W[rb]
;B[fq]
;W[bq]
;B[cn]
;W[bm]
;B[dr]
;W[bo]
;B[bp]
;W[ap]
;B[di]
;W[dj]
;B[fi]
;W[ej]
;B[fg]
;W[oe]
;B[pc]
;W[pf]
;B[ob]
;W[qe]
;B[nc]
;W[od]
;B[pb]
;W[rd]
;B[me]
;W[og]
;B[fj]
;W[fl]
;B[fk]
;W[gl]
;B[cb]
;W[cg]
;B[dg]
;W[bh]
;B[dd]
;W[ef]
;B[ff]
;W[ee]
;B[if]
;W[gh]
;B[ch]
;W[cf]
;B[bi]
;W[ci]
;B[dh]
;W[bj]
;B[fh]
;W[ko]
;B[km]
;W[kq]
;B[lp]
;W[io]
;B[im]
;W[iq]
;B[hp]
;W[lm]
;B[ln]
;W[lr]
;B[mr]
;W[jr]
;B[mm]
;W[hr]
;B[gr]
;W[lo]
;B[ls]
;W[hm]
;B[in]
;W[ho]
;B[hn]
;W[go]
;B[gn]
;W[fo]
;B[er]
;W[cq]
;B[hs]
;W[ir]
;B[dq]
;W[eo]
;B[ep]
;W[em]
;B[hk]
;W[mh]
;B[qm]
;W[mn]
;B[ll]
;W[mp]
;B[mq]
;W[jn]
;B[nn]
;W[mo]
;B[rn]
;W[ro]
;B[pp]
;W[qp]
;B[rq]
;W[rr]
;B[ki]
;W[nl]
;B[ol]
;W[nk]
;B[nm]
;W[kh]
;B[lh]
;W[lg]
;B[li]
;W[mg]
;B[kg]
;W[lf]
;B[bn]
;W[an]
;B[dn]
;W[jm]
;B[jl]
;W[gk]
;B[hj]
;W[rl]
;B[ql]
;W[rk]
;B[gm]
;W[fm]
;B[dm]
;W[dl]
;B[ek]
;W[el]
;B[dk]
;W[ck]
;B[cd]
;W[jf]
;B[jg]
;W[hf]
;B[ie]
;W[gf]
;B[ge]
;W[he]
;B[hd]
;W[fe]
;B[hg]
;W[gg]
;B[hh]
;W[gi]
;B[gj]
;W[rm]
;B[qn]
;W[sn]
;B[bg]
;W[ai]
;B[bd]
;W[ae]
;B[hi]
;W[ge]
;B[ad]
;W[bf]
;B[mi]
;W[ni]
;B[nj]
;W[oj]
;B[mj]
;W[ok]
;B[nh]
;W[ng]
;B[pd]
;W[nf]
;B[pa]
;W[je]
;B[jd]
;W[hl]
;B[il]
;W[gp]
;B[gq]
;W[kr]
;B[jp]
;W[jo]
;B[kp]
;W[ip]
;B[qq]
;W[qr]
;B[oi]
;W[oh]
;B[ni]
;W[mk]
;B[lk]
;W[kn]
;B[lm]
;W[pn]
;B[om]
;W[is]
;B[gs]
;W[ks]
;B[os]
;W[ps]
;B[be]
;W[af]
;B[qa]
;W[ra]
;B[cs]
;W[bs]
;B[ds]
;W[ns]
;B[ms]
;W[os]
;B[eg]
;W[ag]
;B[ei]C[UC: White wins by 5 points
])
(;B[oq]
;W[qq]
(;B[oo])
(;B[lp])))
(;AE[kb][lb][kc][lc][mc][oc][kd][ld][md][nd][qd][le][pe][of][qg]
;W[]C[Let's only look at the black shape in this position. Imagine that the right top corner would be empty]
;B[pd]C[Black would like to play aaaaall the way over here, making a perfect extension from his strength. Always play away from thickness. ]))
(;B[kd]C[Probably its better to play here instead to gain sente.]
;W[kb]
;B[jb]
;W[mb]))
(;B[le]C[For example how about this one? Can't black extend here instead?]
(;W[lc]C[But what happens if white cuts?
There is an interesting tesuji here worth learning. It occurs frequently. But watch out, is is not always a good choice.]
;B[kc]
;W[lb]
;B[mb]
;W[kb]
;B[jb]
;W[jc]
;B[ka]
;W[kd]
;B[la]
;W[kc]
;B[ic]
;W[ke]
;B[lf]
;W[kf]
;B[nf])
(;W[of]C[But this white move is too nice. It seals black up in the corner and connects whites two groups.])))
(;W[]
(;B[cd]C[Black cant wedge]
;W[dd]
;B[bd]
;W[cb]
;B[ea]
;W[be])
(;B[dd]C[The best black can do is..]
;W[de]
;B[cd]
;W[bd]C[But he cant cut]
(;B[bc]
;W[cb]
;B[ea]
;W[bb]C[This result is of course good for white.])
(;B[be]C[This cut does works to some extent]
;W[bf]
;B[bc]
;W[ae]
;B[cb]C[But black ends in gote and white gains fantastic strength on the outside.]))))
(;W[db]C[This doesnt work by the way]
;B[cc]
;W[cb]
;B[bb]
;W[bc]
;B[bd]
;W[ac]
;B[ad]
;W[cd]
;B[ab]
;W[bc]
;B[ac]
;W[dd]
;B[bc]
;W[be]
;B[ca]C[White dies in the corner. Good result for black]))
(;B[ld]C[A high pincer prevents black from being pressed down.]))
(;W[ep]))
(;B[qd]C[This is a game between Cho U playing black and Akiyama Jiro playing white. ]
;W[dd]
;B[pq]
;W[oc]
;B[cp]
;W[qo]
;B[ic]
;W[eq]
;B[pl]
;W[pe]
;B[qe]
;W[pf]
;B[qg]
;W[pg]
;B[qh]
;W[pm]
;B[qm]
;W[pn]
;B[mq]
;W[ql]
;B[qk]
;W[rl]
(;B[pk]
;W[rm]
;B[]LB[qf:A])
(;B[rk])))
