(;SZ[19]AB[qq]AB[qr]AB[pr]AB[or]AB[oq]AB[nq]AB[np]AB[mp]AB[lo]AB[ko]AB[mn]AB[pn]AB[qn]AB[qo]AB[ql]AB[pl]AB[ol]AB[pk]AB[nk]AB[rk]AB[qj]AB[qi]AB[qh]AB[rg]AB[sg]AB[sf]AB[se]AB[re]AB[rd]AB[qe]AB[qc]AB[pd]AB[pc]AB[pb]AB[oc]AB[nb]AB[mb]AB[lb]AB[lc]AB[ld]AB[le]AB[me]AB[nf]AB[fp]AB[fo]AB[fq]AB[fh]AB[fg]AB[ef]AB[df]AB[cf]AB[ce]AB[bd]AB[ae]AB[co]AB[dn]AB[dm]AB[cm]AB[bk]AB[bj]AB[cj]AB[dj]AB[jn]AB[jo]AW[do]AW[dp]AW[dq]AW[cn]AW[bn]AW[bm]AW[bl]AW[cl]AW[ck]AW[gh]AW[gg]AW[ff]AW[fe]AW[ee]AW[de]AW[cd]AW[bc]AW[dc]AW[hd]AW[kb]AW[jc]AW[gp]AW[hq]AW[mc]AW[nc]AW[md]AW[nd]AW[od]AW[oe]AW[pe]AW[of]AW[og]AW[rf]AW[qf]AW[qg]AW[rh]AW[ph]AW[pi]AW[pj]AW[ok]AW[mj]AW[mh]AW[ln]AW[kp]AW[lp]AW[lq]AW[mr]AW[nr]AW[mo]AW[no]AW[oo]AW[po]AW[op]AW[pp]AW[pq]AW[qp]AW[rp]AW[qm]AW[kn]TR[mp]TR[np]TR[nq]TR[oq]TR[or]TR[pr]TR[qr]TR[qq]C[Black has cut at 'a'. White to play and kill the marked stones without ko.]LB[mn:a]FF[4]GM[1]AP[Jago:Version 4.18]GN[temp] (;W[rq];B[rr] (;W[mm];B[sr] (;W[os];B[ps];W[rs];B[nn] (;W[on];B[nm] (;W[om];B[nl];W[pm];B[rm];W[rn]C[White should win from this position (many variations) but black can get a ko or seki if he slips. RIGHT]) (;W[pm];B[rm];W[om];B[nl];W[rn]C[White should win from this position (many variations) although black can get a ko or seki if he slips. RIGHT]) (;W[rm];B[pm])) (;W[nm];B[on]) (;W[pm];B[on];W[om];B[nm]) (;W[rm];B[on])) (;W[rs];B[os]C[White's best is now a ko due to black's large eyespace.]) (;W[qs];B[os]C[White's best is now a ko due to black's large eyespace.])) (;W[sr];B[nn]C[white loses race]) (;W[os];B[nn]C[white loses race]) (;W[nn];B[sr];W[os];B[ps];W[rs];B[mm] (;W[nm];B[nl] (;W[pm];B[rm];W[rn];B[ro]) (;W[rm];B[om] (;W[rn];B[ro]) (;W[rn];B[ro]) (;W[ro];B[rn])) (;W[om];B[pm]) (;W[rn];B[ro] (;W[pm];B[rm]) (;W[om];B[pm]))) (;W[pm];B[rm] (;W[nm];B[nl];W[rn];B[ro]) (;W[om];B[nm];W[on];B[ro])) (;W[om];B[pm] (;W[nm];B[nl]) (;W[ml];B[nm])) (;W[ml];B[nm];W[om];B[pm]) (;W[on];B[om];W[nm];B[nl]) (;W[rn];B[ro];W[nm];B[nl];W[pm];B[rm])) (;W[nm];B[sr];W[os];B[ps];W[rs];B[mm] (;W[nl];B[nn] (;W[on];B[om];W[ml];B[lm];W[km];B[ll]) (;W[om];B[on] (;W[pm];B[rm]) (;W[rn];B[pm]) (;W[rm];B[pm])) (;W[pm];B[om];W[on];B[rm];W[ml];B[lm];W[km];B[ll]) (;W[rm];B[pm];W[on];B[ml])) (;W[om];B[nl] (;W[pm];B[rm];W[rn];B[ro]) (;W[rm];B[pm])) (;W[pm];B[rm] (;W[nl];B[nn] (;W[on];B[om];W[ml];B[lm];W[km];B[ll]) (;W[om];B[on]) (;W[rn];B[ro];W[on];B[om]) (;W[ml];B[on])) (;W[om];B[nl];W[rn];B[ro]) (;W[nn];B[nl];W[rn];B[ro]))) (;W[on];B[sr];W[os];B[ps];W[rs];B[mm] (;W[pm];B[rm] (;W[nm];B[nl] (;W[rn];B[om]) (;W[om];B[ro])) (;W[om];B[nm]) (;W[rn];B[om];W[ro];B[nn]) (;W[ml];B[nm] (;W[om];B[ro];W[nl];B[lm]) (;W[rn];B[om];W[ro];B[sn])) (;W[nl];B[nm];W[om];B[ro];W[ml];B[lm])) (;W[om];B[pm] (;W[ml];B[nm];W[nl];B[lm]) (;W[nl];B[nm];W[ml];B[lm]) (;W[nm];B[nl])) (;W[rm];B[pm];W[nm];B[nl]) (;W[nm];B[nl];W[pm];B[rm] (;W[rn];B[om];W[ro];B[nn]) (;W[om];B[ro]))) (;W[om];B[sr];W[os];B[ps];W[rs];B[mm] (;W[nm];B[nl] (;W[pm];B[rm];W[rn];B[ro]) (;W[rn];B[ro] (;W[pm];B[rm]) (;))) (;W[rn];B[ro] (;W[pm];B[rm];W[nm];B[nl]) (;W[nm];B[nl];W[pm];B[rm])) (;W[pm];B[rm] (;W[rn];B[ro];W[nm];B[nl]) (;W[nm];B[nl];W[rn];B[ro]))) (;W[pm];B[sr];W[os];B[ps];W[rs];B[mm] (;W[rm];B[on] (;W[om];B[nn]) (;W[nn];B[om];W[nm];B[nl])) (;W[om];B[rm];W[rn];B[ro];W[nm];B[nl]) (;W[nm];B[nl];W[rm];B[on] (;W[nn];B[om]) (;W[om];B[nn])) (;W[on];B[rm] (;W[rn];B[om];W[ro];B[nn]) (;W[om];B[ro];W[nm];B[nl]) (;W[nm];B[nl];W[rn];B[om];W[ro];B[nn]) (;W[ml];B[nm];W[om];B[ro];W[nl];B[lm])) (;W[nn];B[rm] (;W[nm];B[nl];W[rn];B[ro]) (;W[om];B[nm];W[on];B[ro]) (;W[rn];B[ro];W[nm];B[nl])))) (;W[mm];B[rq] (;W[sr];B[sq] (;W[os];B[ps];W[rs];B[ro];W[sp];B[nn];W[on];B[nm] (;W[om];B[nl];W[pm];B[rm]) (;W[pm];B[rm])) (;W[rs];B[os];W[qs];B[ro];W[sp];B[nn];W[on];B[nm] (;W[pm];B[rm]) (;W[om];B[nl];W[pm];B[rm]))) (;W[rs];B[sn] (;W[nn];B[sp] (;W[ro];B[so] (;W[rn];B[rm]) (;W[rm];B[rn];W[pm];B[om];W[on];B[sm])) (;W[rn];B[ro] (;W[pm];B[rm]) (;W[rm];B[pm])) (;W[sm];B[rm];W[ro];B[so];W[rn];B[sl])) (;W[sp];B[nn];W[on];B[nm];W[om];B[nl];W[pm];B[rm]) (;W[so];B[os] (;W[qs];B[nn];W[on];B[nm] (;W[om];B[nl];W[pm];B[rm];W[rn];B[sm] (;W[sq];B[sr]C[ko]) (;W[ro];B[qn];W[sq];B[sr]C[ko])) (;W[pm];B[rm];W[om];B[nl];W[rn];B[sm] (;W[sq]C[ko];B[sr]C[ko]) (;W[ro];B[qn];W[sq]C[ko];B[sr]C[ko]))) (;W[sq];B[sr];W[qs];B[nn];W[on];B[nm] (;W[om];B[nl];W[pm];B[rm];W[rn];B[sm]C[ko]) (;W[pm];B[rm];W[om];B[nl];W[rn];B[sm]C[ko])) (;W[sr];B[sq];W[qs];B[nn];W[on];B[nm] (;W[om];B[nl];W[pm];B[rm];W[rn];B[sm]C[white loses race]) (;W[pm];B[rm];W[om];B[nl];W[rn];B[sm]C[white loses race]))) (;W[sq];B[nn];W[on];B[nm] (;W[om];B[nl];W[pm];B[rm]) (;W[pm];B[rm];W[om];B[nl])) (;W[ro];B[nn];W[on];B[nm];W[om];B[nl];W[pm];B[rm];W[rn];B[qn] (;W[so];B[sm];W[sq];B[sr]C[ko]) (;W[sq];B[sr];W[so];B[sm]C[ko]))) (;W[os];B[ro] (;W[sp];B[nn];W[on];B[nm] (;W[om];B[nl];W[pm];B[rm]) (;W[pm];B[rm];W[om];B[nl])) (;W[sq];B[nn];W[on];B[nm] (;W[om];B[nl];W[pm];B[rm]) (;W[pm];B[rm])) (;W[so];B[sq] (;W[rs];B[sp]) (;W[sp];B[rs]))) (;W[sq];B[sr];W[rs];B[ro];W[sp];B[nn] (;W[on];B[nm] (;W[om];B[nl];W[pm];B[rm]) (;W[pm];B[rm];W[rr];B[qs])) (;W[rr];B[on];W[ss];B[so]))) (;W[rr];B[rq] (;W[sq];B[nn]) (;W[mm];B[rs]C[black lives])) (;W[os];B[rq];W[mm];B[ro] (;W[sp];B[nn];W[on];B[nm] (;W[om];B[nl];W[pm];B[rm]) (;W[pm];B[rm];W[om];B[nl])) (;W[sq];B[nn];W[on];B[nm];W[om];B[nl];W[pm];B[rm]) (;W[so];B[sq] (;W[sp];B[rs]) (;W[rs];B[sp]))) (;W[nm];B[rq] (;W[rs];B[os];W[qs];B[mm] (;W[nl];B[nn];W[on];B[om]) (;W[om];B[nl] (;W[pm];B[rm];W[rn];B[ro]) (;W[rn];B[ro];W[pm];B[rm])) (;W[pm];B[rm] (;W[rn];B[ro];W[om];B[nl]) (;W[om];B[nl];W[rn];B[ro])) (;W[rn];B[ro];W[pm];B[rm];W[om];B[nl]) (;W[ml];B[lm] (;W[nl];B[nn] (;W[on];B[om]) (;W[om];B[on];W[pm];B[rm])) (;W[ll];B[nn] (;W[on];B[km] (;W[pm];B[om] (;W[rm];B[ro]) (;W[rn];B[rm])) (;W[om];B[nl];W[pm];B[rm];W[rn];B[sp];W[ro];B[qn];W[sm];B[rl])) (;W[om];B[on];W[pm];B[ro]) (;W[pm];B[on])))) (;W[os];B[ro] (;W[sp];B[mm] (;W[nn];B[nl] (;W[pm];B[om]) (;W[om];B[pm])) (;W[ml];B[nn];W[on];B[lm] (;W[km];B[ll] (;W[om];B[nl] (;W[pm];B[rm]) (;W[mk];B[kl];W[jm];B[pm])) (;W[nl];B[om]) (;W[mk];B[om]) (;W[pm];B[om])) (;W[om];B[nl];W[pm];B[rm]) (;W[nl];B[om]) (;W[ll];B[km] (;W[om];B[nl];W[pm];B[rm]) (;W[pm];B[om]))) (;W[nn];B[nl] (;W[pm];B[om]) (;W[om];B[pm])) (;W[om];B[nl] (;W[rm];B[pm]) (;W[pm];B[rm]))) (;W[sq];B[mm] (;W[ml];B[nn] (;W[on];B[lm] (;W[km];B[ll] (;W[lk] (;B[kl] (;W[jm];B[om]) (;W[om];B[nl];W[pm];B[rm]) (;W[pm];B[om])) (;)) (;W[pm];B[om]) (;W[om];B[nl];W[pm];B[rm])) (;W[pm];B[om]) (;W[om];B[nl];W[pm];B[rm])) (;)) (;W[nn];B[nl] (;W[pm];B[om]) (;W[om];B[pm])) (;W[om];B[nl];W[pm];B[rm]) (;W[pm];B[nl] (;W[rm];B[on]) (;W[om];B[rm])) (;W[nl];B[nn];W[on];B[om]))) (;W[sq];B[sr];W[rs];B[ro];W[sp];B[mm] (;W[ml];B[nn];W[on];B[lm] (;W[km];B[ll] (;W[lk];B[kl] (;W[jm];B[om]) (;W[om];B[nl];W[pm];B[rm]) (;) (;W[rr];B[om];W[ss];B[so]) (;W[pm];B[om])) (;W[om];B[nl];W[pm];B[rm]) (;W[rr];B[om];W[ss];B[so]) (;W[pm];B[om])) (;) (;W[om];B[nl];W[pm];B[rm]) (;W[pm];B[om]) (;W[rr];B[om];W[ss];B[so])) (;W[nn];B[nl] (;W[om];B[pm]) (;W[pm];B[om])) (;W[om];B[nl];W[pm];B[rm]) (;W[pm];B[nl] (;W[rm];B[on]) (;W[om];B[rm])) (;W[nl];B[nn];W[on];B[om])) (;W[sr];B[sq] (;W[rs];B[os];W[qs];B[ro];W[sp];B[mm] (;W[ml];B[nn];W[on];B[lm] (;W[km];B[ll] (;W[lk];B[kl] (;W[jm];B[om]) (;W[om];B[nl];W[pm];B[rm])) (;W[om];B[nl];W[pm];B[rm]) (;W[pm];B[om])) (;W[om];B[nl];W[pm];B[rm]) (;W[pm];B[om])) (;W[om];B[nl] (;W[pm];B[rm]) (;)) (;W[pm];B[nl] (;W[rm];B[on]) (;W[om];B[rm])) (;W[nn];B[nl];W[pm];B[om]) (;W[nl];B[nn];W[on];B[om])) (;W[os];B[ro];W[sp];B[mm] (;W[ml];B[nn];W[on];B[lm] (;W[km];B[ll] (;W[lk];B[kl] (;W[jm];B[om]) (;W[om];B[nl];W[pm];B[rm]) (;W[pm];B[om])) (;W[om];B[nl];W[pm];B[rm]) (;W[pm];B[om])) (;W[om];B[nl];W[pm];B[rm]) (;W[pm];B[om])) (;W[om];B[nl];W[pm];B[rm]) (;W[pm];B[nl] (;W[om];B[rm]) (;W[rm];B[on])) (;W[nn];B[nl];W[pm];B[om]) (;W[nl];B[nn];W[on];B[om])))))