(;GM[1]FF[4]CA[UTF-8]AP[CGoban:3]ST[2]
RU[Japanese]SZ[19]KM[0.00]
GN[ ]PW[ ]PB[ ]AW[fa][ra][fb][gb][hb][ib][ob][rb][fc][ic][mc][oc][pc][qc][bd][cd][dd][ed][fd][gd][qd][rd][be][de][ge][he][bf][cf][ef][nf][eg][gg][hg][ig][ah][bh][ch][eh][hh][rh][sh][ci][di][ei][fi][gi][ii][oi][pi][qi][gj][hj][ij][mj][oj][rj][ik][jk][kk][lk][mk][nk][ok][pk][qk][kl][ql][rl][sl][km][nm][om][fn][kn][ln][nn][pn][qn][rn][jo][ko][mo][no][oo][po][ap][bp][cp][dp][kp][np][dq][lq][oq][br][dr][er][lr][mr][or][pr][cs][fs][ms][ps]AB[ba][na][bb][eb][jb][kb][mb][nb][ac][bc][cc][dc][ec][hc][kc][nc][hd][id][ld][nd][od][pd][ie][je][me][oe][pe][qe][re][se][jf][mf][of][fg][jg][kg][mg][qg][rg][jh][lh][mh][nh][oh][ph][qh][ai][bi][ji][mi][bj][cj][dj][ej][jj][kj][lj][nj][ck][ek][gk][hk][dl][el][il][jl][bm][cm][fm][gm][hm][jm][bn][dn][en][gn][in][jn][bo][co][do][go][ho][io][qo][ro][so][fp][gp][ip][jp][rp][fq][pq][qq][rq][sq][fr][gr][hr][ir][jr][kr][qr][ks][ls]C[Problem C-19 in Berlekamp and Wolfe's "Mathematical Go", revised by Bill Spight.
White to play and win.]PM[2]
;B[]
(;W[ea]C[1pt sente])
(;W[qs]C[1pt sente, but not as sente as the other one. Problably sente enough, though])
(;W[ja]C[2pt gote])
(;W[ni]C[2pt gote])
(;W[oa]C[1pt reverse sente, but the black sente is only 99% sente])
(;W[sd]C[1pt reverse sente, but the black sente is even less sente then the other one])
(;W[sg]C[miai count is 2 pt gote(1pt miai value), but I believe it to be slighly better than the "pure" 2pt gote at o11, because it has got a slight "sente touch" to it(it would be 1pt sente if b answers and at some point, b will answer, because) ]
;B[]
;W[sf]
;B[]
;W[rf]
;B[]
;W[qf]
;B[]
;W[pf]
;B[]
;W[pg]
;B[]
;W[og]C[this is now sente because the follow up would be 3pt gote])
(;W[ep]C[also 2 pt gote. hard for me to compare to o11 and t13. the follow up at e5 is sente, because it again threatens a 2pt gote..])
(;W[ao]C[2pt gote miai count. But I believe it to be slightly better than that, because arriving at a7 would be sente. I would rate this a little better than t13, because "the corridor to the sente is shorter"]
;B[]
;W[an]
;B[]
;W[am]
;B[al])
(;W[jc]C[2pt gote (surprise...).I think that arriving at l16 will be sente, also at k16, has a minimal sentish touch(maybe getting the cut at m17, is worth some epsilon, though I cant see it)])
(;W[sn]C[2pt gote with a slighly "reverse sente"-ish touch because  the black move has a sente touch after a very long corridor.])
(;W[ad]C[similiar to t6, slighly reverse sente-ish touch, but better than t6, because the black move is a little more sente ])
(;W[pp]C[2 points gote, plus it makes r1 from "just sente" to absolutely sente. There is also a seki at s1, but I dont think its relevant, because it only works after r4 is filled, but r1 will be taken long before that. It also might give an additional ko threat in the corner after the dame are filled, because the eye is gone, but there seem to be no kos. In total its definitely better than k19/o11, but I dont know how it compares to t13, for example.])
(;W[fj]C[2 pt gote. THe follow up in the end is gote, so this seems very similar to e4(maybe they are miai?)])
(;W[if]C[2pt gote with a reverse sente touch(better than a16 and t6, in my feeling)])
(;W[kq]C[2 pt gote. Similar(even the same,imo) to e4 and f10])
(;W[gs]C[Also this move is 1pt miai value as all the others, but it's hardest for me to count. Black g1 would create another 2 point gote at e1. Now if white plays it, then h1 is sente for black (roundabout 1 point), but black can also not take it, because afer white h1, it still leaves a move worth the same miai value(with j1 now really being 1pt sente for black). So no clue, whether withe g1 is better or worse than an ordinary 2pt gote(like o11), I would estimate it worse than the move, who have "a sente touch" for me, like k17, t13... ]))