Life In 19x19

(;AB[dr][cq][dp][do][co][cn][dm][em][en][di][ci][bi][bh][ei][eh][eg][fj][gj][cd][gc][jd][kb][jg][jj][mh][ph][pi][qj][qk][pl][rl][rm][qm][pn][po][pp][op][np][oq][or][qq][rq][rr][ns][mq][lq][kr][ls][kp][ip][ko][kn][km][kl][ll][nk][qb][pb][pd][qd][od][oc]AW[pc][qc][ob][na][mb][nc][nd][lc][cc][dc][dd][de][cf][bg][ch][dh][fi][ej][fk][el][dl][ck][cm][bm][fm][gm][gl][eo][fo][fq][er][hq][jq][kq][jr][js][lp][mp][pr][qr][pq][qp][qn][qo][rp][sq][rs][pm][om][ol][on][no][ln][lm][ml][mk][mj][lk][ni][pj][pk]SZ[19]C[White plays.

With a territorial lead, Black only needs to save his center stones (without endangering his left side group) to win?

So White needs a splitting attack between the weak left side and center groups.]

(;W[ij]C[A splitting attack that seems to give practical chances to equally pressure Black's 2 stones on the left and the center stones on the right. ]
(;B[hi]C[Defending the left in the top direction, ...];W[jk]C[... White immediately cuts off the center group.])
(;B[hk]C[Defending the left in the bottom direction ...];W[ik]C[... seems to let White keep the splitting attack going. Looks complicated!])
(;B[hj]C[Defending the left group with the clamp, ...];W[jk]C[... seems to fail to this cut.])
(;B[ji]C[Black doesn't have time to rescue the center stones this way?];W[gi];B[hj];W[ik]C[Black seems to lose either the left or center group.]))
(;W[hj]C[A splitting attack, but a bit too far from Black's group on the right.];B[gi]C[Black saves the weak stones to the left, and White has no good follow up to cut off the center stones to the right?];W[jk]C[For example?];B[kk];W[kj];B[ik];W[jl];B[il];W[jm];B[in];W[ji];B[ij]C[White is too thin to cut off the center stones.]
)
(;W[ji]C[Too soft];B[ij]C[Black seems strong everywhere now.]))

(;GM[1]FF[4]AP[Drago:4.12]SZ[19]CA[UTF-8]AW[pc][qc][ob][na][mb][nc][nd][lc][cc][dc][dd][de][cf][bg][ch][dh]
[fi][ej][fk][ck][el][dl][cm][bm][er][fq][fo][eo][fm][gm][gl][hq]
[jq][jr][js][kq][lk][mk][mj][ni][pj][pk][qn][qo][qp][rp][sq][rs]
[qr][pr][pq][pm][om][ol][on][no][mp][lp][ln][lm][ml]AB[qb][pb][qd][pd][od][oc][kb][jd][gc][cd][eg][eh][ei][di][ci][bi]
[bh][fj][gj][dm][em][en][cn][co][do][dp][cq][dr][ip][kp][ko][kn]
[km][kl][ll][jj][jg][mh][pi][ph][qj][qk][pl][rl][rm][qm][qq][rq]
[rr][or][oq][op][pp][pn][po][lq][mq][kr][np][ls][ns][nk]C[White to move

The black stones in the center are thin, how should White exploit the thinness and be victorious?];W[ij]C[Right

The vital shape point]
(;B[hk]C[Influenced by White's move, Black makes a diagonal. A straight out resistance leads to even greater loss.];W[ik]C[Drives Black towards the bottom. The center is very unlikely for Black to regain control at this point.];B[hl]
;W[ji]C[The right order of sequence. Now White has basically connected with the group to the right.];B[hi]LB[gi:A]C[Black must reinforce else White plays at A and cuts off Black.];W[il];B[hm];W[im];B[hn];W[in];B[ho]
;W[jp]C[After this push, White has surrounded the 7 Black stones and is in a great position.];B[ii]
;W[ki]C[White has successfully profited by around 20 points in the center])
(;B[ik]C[Black tries to resist];W[hk]C[Good]
(;B[hj]C[Black can only cut];W[ii]
(;B[gh]C[To gain life first for the group on the left.];W[jk];B[il]
;W[ki]C[White nets and connects up with the group on the right];B[kk]
;W[kj]C[Black is clearly going to lose])
(;B[ji]C[Black tries to stop White from linking with the group on the right.];W[gh]C[Strong as Black has no good reply.];B[hi]C[Blacks three stones are being driven];W[ih];B[hh];W[gg]
;B[ff]C[Black needs to play here because if he allows White to play here, the Black group on the left will be captured.];W[ig];B[hg];W[if];B[hf];W[jk];B[il]
;W[jh]C[Black's central group is clearly in danger now.]))
(;B[ii]C[poor];W[hj]C[Black's group on the left becomes very weak])))