(;TR[pp]LB[or:a]LB[qp:b]AB[jp][lq][mp][mq][mr][nq][pk][po][pq][qj][qk][ql][qo][qq][rm]AW[no][np][nr][ol][oq][pl][pn][pp][qn][rk][rn][ro][rp]C[FORCE]AP[goproblems autoextractor]PW[j13]PB[DJAkon]PC[The KGS Go Server at http://www.gokgs.com/]DT[2010-01-30]PL[B] (;B[or]TR[qq]TR[pq]C[Playing here is worth about 12 points over playing away in an empty corner. The stones marked with a triangle are stronger. White would have played at the same place if you played away. Your move prevents white from making about 14 points in the corner. RIGHT]) (;B[qp];W[op]TR[qq]TR[pq]C[This loses about 8 points. The stones marked with a triangle are dead. White makes about 9 corner points. ]))