Problem	16335
Created	2012-07-23
Source	Problem 1434
Rating

Difficulty	8 dan
Average Solve Time	76 secs
User Attempts	64 / 329
Solve Ratio Rating	1 kyu
	rating history

Problem 1434's defense is not optimal. Can you do better? There are no big ko threats.

(;AB[sd]AB[rd]AB[qd]AB[qe]AB[pe]AB[pc]AB[nd]AB[md]AB[ld]AB[me]AB[kc]AB[kb]AB[la]AB[mb]AB[oc]AW[se]AW[re]AW[qf]AW[rg]AW[rh]AW[sh]AW[pf]AW[oe]AW[od]AW[pd]AW[ne]AW[mf]AW[le]AW[kd]AW[ke]AW[je]AW[jc]AW[jb]AW[ja]AW[ka]AW[kf]AW[qc]C[White to play.]SZ[19]AB[rc] (;W[qb];B[rb] (;W[nc] (;B[pb]C[MoreKnock's variationCHOICE] (;W[mc];B[nb] (;W[lc];B[lb]C[Black gets only 6 points from the corner, loss included. Best result for both.RIGHT]) (;W[lb];B[lc]) (;W[qa];B[lc]) (;W[pa];B[lc]) (;W[ma];B[lc]C[Ko for just a few points])) (;W[nb];B[mc] (;W[na];B[oa]) (;W[oa];B[qa];W[ma];B[na]C[Ko, and Black can cut the losses anyway by playing P18 instead of ko.]) (;W[lb];B[na] (;W[lc];B[ob]) (;W[ma];B[ob]))) (;W[lc];B[mc] (;W[lb];B[na]C[About 3 points worse than possible.]) (;W[nb] (;B[lb] (;W[oa];B[qa];W[ma];B[na]C[Ko]) (;W[na];B[oa]) (;W[ob];B[qa]) (;W[qa];B[na]) (;W[pa];B[qa])) (;B[na]C[If Black does not want to fight the ko this will still be worse for White than the solution.])) (;W[na];B[lb];W[nb];B[oa])) (;W[lb];B[lc]) (;W[ob];B[qa] (;W[mc];B[nb] (;W[lc];B[lb]C[Black gets only 6 points from the corner, loss included.RIGHT]) (;W[lb];B[lc])) (;W[nb];B[mc]) (;W[lc];B[mc] (;W[lb];B[na]C[About 3 points worse than the solution.]) (;W[na];B[lb])) (;W[lb];B[lc])) (;W[qa];B[mc])) (;B[mc]C[Black wants to save it all, now make him pay for it.CHOICE] (;W[ob];B[nb] (;W[pb];B[nc] (;W[ra];B[qa] (;W[pa];B[sb] (;W[lb];B[lc];W[na]C[Gote seki. Black was a bit greedy and pays for it.RIGHT]) (;W[na];B[ma] (;W[lb];B[oa]C[Ko, Black takes first. Just capturing those two stones is not enough.]TR[kb]TR[kc]) (;W[lc];B[oa]C[Ko, Black takes first. Just capturing those two stones is not enough.]TR[kb]TR[kc])) (;W[lc];B[lb];W[na]C[Gote seki. Black was a bit greedy and pays for it.RIGHT])) (;W[sb];B[sa]C[Ko, Black takes first. You have no big threats, remember.]) (;W[na];B[sa] (;W[oa];B[ma]C[2 stones are not enough.]) (;W[lb];B[oa] (;W[ma];B[pa]C[Just a tiny reduction.]) (;W[lc];B[pa]C[Black gets about 9 points from the corner, levelling out White's gain.]) (;W[pa] (;B[lc] (;W[ra];B[of]C[Err...] (;W[nf];B[qa]C[Ko, Black takes first.]) (;W[sb];B[nf])) (;W[sb];B[oa])) (;B[oa]C[If Black really does not like the ko this reduces the loss anyway.])) (;W[sb];B[lc])) (;W[lc];B[oa] (;W[lb];B[pa]C[Black gets about 9 points from the corner, levelling out White's gain.]) (;W[pa];B[lb] (;W[ra];B[of]C[Whoops!] (;W[nf];B[qa]C[Ko, Black takes first.]) (;W[sb];B[nf])) (;W[sb];B[oa])) (;W[sb];B[lb])) (;W[sb];B[pa])) (;W[oa];B[na]) (;W[lb];B[oa]C[Just 2 stones.]) (;W[lc];B[oa]C[Only 2 stones.])) (;W[sb];B[ra] (;W[na];B[qa]) (;W[lb];B[lc];W[na];B[qa]) (;W[lc];B[lb];W[na];B[qa])) (;W[na];B[ra] (;W[lb];B[lc] (;W[oa];B[qa]) (;W[sb];B[qa])) (;W[lc];B[lb] (;W[oa];B[qa]) (;W[sb];B[qa]))) (;W[lb];B[oa]C[2 stones is not enough.]) (;W[lc];B[oa]C[2 stones is not enough.]) (;W[oa];B[na]) (;W[qa];B[ra]) (;W[pa];B[ra])) (;W[ra];B[pb]) (;W[pa];B[ra]) (;W[oa];B[pb]) (;W[qa];B[pb]) (;W[lb];B[pb]C[2 stones is not enough.]) (;W[lc];B[pb]C[2 stones is not enough.]) (;W[sb];B[pb])) (;W[nb];B[ob] (;W[ra];B[sb] (;W[na];B[pa] (;W[qa];B[ma]C[2 stones is not enough.]TR[kc]TR[kb]) (;W[lb];B[oa] (;W[lc];B[ma]C[2 stones is not enough.]) (;W[ma];B[la]C[2 stones is not enough.]) (;W[qa];B[ma]C[2 stones is not enough.])) (;W[lc];B[oa] (;W[lb];B[ma]C[2 stones is not enough.]) (;W[qa];B[ma]C[2 stones is not enough.]))) (;W[qa];B[pa] (;W[na];B[ma]C[2 stones is not enough.]TR[kc]TR[kb]) (;W[lb];B[na]C[2 stones is not enough.]) (;W[lc];B[na]C[2 stones is not enough.])) (;W[pb];B[na]) (;W[pa];B[na]) (;W[oa];B[na]) (;W[lb];B[na]C[2 stones is not enough.]) (;W[lc];B[lb])) (;W[na];B[qa]) (;W[qa];B[pa] (;W[na];B[ra]) (;W[ra];B[sb] (;W[na];B[ma]C[2 stones is not enough.]TR[kc]TR[kb]) (;W[lb];B[na]C[2 stones is not enough.]) (;W[lc];B[na]C[2 stones is not enough.])) (;W[lb];B[na]C[2 stones is not enough.]) (;W[lc];B[na]C[2 stones is not enough.])) (;W[pa];B[na]) (;W[lb];B[lc]) (;W[lc];B[lb]) (;W[oa];B[na]) (;W[sb];B[qa])) (;W[pb];B[ob]) (;W[qa];B[ra] (;W[ob];B[nb];W[pb];B[nc]) (;W[pb];B[ob]) (;W[nb];B[ob]) (;W[oa];B[ob]) (;W[pa];B[oa])) (;W[pa] (;B[ob];W[oa];B[na];W[ra];B[sb]) (;B[nb])) (;W[oa];B[ob] (;W[pa];B[na];W[ra];B[sb]) (;W[na];B[pa] (;W[qa];B[ra]) (;W[ra];B[pb]) (;W[nb];B[ma])) (;W[ra];B[sb];W[pa];B[na])) (;W[lb];B[nb]C[2 stones is not enough.]) (;W[lc];B[nb]C[2 stones is not enough.])) (;B[nb] (;W[lc];B[mc]C[That's just 2 stones.]) (;W[ob];B[mc] (;W[lb];B[pb]C[2 stones is not enough.]) (;W[lc];B[pb]C[2 stones is not enough.]) (;W[na]) (;W[pb];B[nc] (;W[ra];B[qa] (;W[pa];B[sb] (;W[lb];B[lc];W[na]C[Gote seki. Black was a bit greedy and pays for it.RIGHT]) (;W[na];B[ma] (;W[lb];B[oa]C[Ko, Black takes first. Just capturing those two stones is not enough.]TR[kb]TR[kc]) (;W[lc];B[oa]C[Ko, Black takes first. Just capturing those two stones is not enough.]TR[kb]TR[kc])) (;W[lc];B[lb];W[na]C[Gote seki. Black was a bit greedy and pays for it.RIGHT])) (;W[sb];B[sa]C[Ko, Black takes first. You have no big threats, remember.]) (;W[na];B[sa] (;W[oa];B[ma]C[2 stones are not enough.]) (;W[lb];B[oa] (;W[ma];B[pa]C[Just a tiny reduction.]) (;W[lc];B[pa]C[Black gets about 9 points from the corner, levelling out White's gain.]) (;W[pa] (;B[lc] (;W[ra];B[of]C[Err...] (;W[nf];B[qa]C[Ko, Black takes first.]) (;W[sb];B[nf])) (;W[sb];B[oa])) (;B[oa]C[If Black really does not like the ko this reduces the loss anyway.])) (;W[sb];B[lc])) (;W[lc];B[oa] (;W[lb]) (;W[pa];B[lb] (;W[ra];B[of]C[Whoops!] (;W[nf];B[qa]C[Ko, Black takes first.]) (;W[sb];B[nf])) (;W[sb];B[oa])) (;W[sb];B[lb])) (;W[sb];B[pa])) (;W[oa];B[na]) (;W[lb];B[oa]C[Just 2 stones.]) (;W[lc];B[oa]C[Only 2 stones.])) (;W[sb];B[ra] (;W[na];B[qa]) (;W[lb];B[lc];W[na];B[qa]) (;W[lc];B[lb];W[na];B[qa])) (;W[na];B[ra] (;W[lb];B[lc] (;W[oa];B[qa]) (;W[sb])) (;W[lc];B[lb] (;W[oa];B[qa]) (;W[sb]))) (;W[lb];B[oa]C[2 stones is not enough.]) (;W[lc];B[oa]C[2 stones is not enough.]) (;W[oa];B[na]) (;W[qa];B[ra]) (;W[pa];B[ra])) (;W[oa];B[pb]) (;W[pa];B[ra]) (;W[qa];B[pb]) (;W[ra];B[pb]) (;W[sb];B[pb])))) (;W[lc];B[mc]C[2 stones is not enough.]) (;W[lb];B[lc] (;W[nc];B[pb]) (;W[ob];B[pb])) (;W[ob];B[nc] (;W[pb];B[nb] (;W[ra];B[sb] (;W[na];B[lc]) (;W[lc];B[qa] (;W[pa] (;B[na];W[lb];B[oa]) (;B[oa];W[na];B[ma])) (;W[na];B[pa] (;W[oa];B[qa]) (;W[lb];B[oa])) (;W[oa];B[na])) (;W[qa];B[oa] (;W[na];B[lc]) (;W[lc];B[na];W[lb];B[pa]C[Just capturing those two stones is not enough.]))) (;W[lc];B[oa]C[Black lives with points]) (;W[na];B[lc])) (;W[lc];B[pb]C[Black lives with points]) (;W[nb];B[pb])) (;W[pb];B[ob]) (;W[nb];B[nc] (;W[pb];B[ob]) (;W[ob];B[pb]) (;W[lc];B[lb])) (;W[ra];B[pb] (;W[nc];B[mc]) (;W[lc];B[lb];W[nc];B[mc])) (;W[qa];B[pb] (;W[nc];B[mc]) (;W[ra];B[pa]) (;W[pa];B[nc]) (;W[lc];B[lb] (;W[nc];B[mc]) (;W[pa];B[nc]))) (;W[mc];B[nc])) (;W[rb];B[qb]) (;W[nc] (;B[qb]C[CHOICE] (;W[lc];B[mc]C[2 stones is not enough.]) (;W[mc];B[nb]C[] (;W[lc];B[lb]C[Right, after losses Black keeps 6 points.RIGHT]) (;W[lb];B[lc])) (;W[nb];B[mc]) (;W[lb];B[lc]) (;W[ob];B[mc])) (;B[mc]C[Black wants to save all, now make him pay for it.CHOICE] (;W[qb];B[rb] (;W[lc];B[nb]C[2 stones is not enough.]) (;W[lb];B[nb]C[2 stones is not enough.]) (;W[nb];B[ob] (;W[ra];B[sb] (;W[na];B[pa] (;W[qa];B[ma]C[2 stones is not enough.]TR[kc]TR[kb]) (;W[lb];B[oa] (;W[lc];B[ma]C[2 stones is not enough.]) (;W[ma];B[la]C[2 stones is not enough.]) (;W[qa];B[ma]C[2 stones is not enough.])) (;W[lc];B[oa] (;W[lb]) (;W[qa];B[ma]C[2 stones is not enough.]))) (;W[qa];B[pa] (;W[na]) (;W[lb];B[na]C[2 stones is not enough.]) (;W[lc];B[na]C[2 stones is not enough.])) (;W[pb];B[na]) (;W[pa];B[na]) (;W[oa];B[na]) (;W[lb];B[na]C[2 stones is not enough.]) (;W[lc];B[lb])) (;W[na];B[qa]) (;W[qa];B[pa] (;W[na];B[ra]) (;W[ra];B[sb] (;W[na]) (;W[lb]) (;W[lc])) (;W[lb];B[na]C[2 stones is not enough.]) (;W[lc];B[na]C[2 stones is not enough.])) (;W[pa];B[na]) (;W[lb];B[lc]) (;W[lc];B[lb]) (;W[oa];B[na]) (;W[sb];B[qa])) (;W[ob];B[nb] (;W[pb];B[nc] (;W[ra];B[qa] (;W[pa];B[sb] (;W[lb];B[lc];W[na]C[Gote seki. Black was a bit greedy and pays for it.RIGHT]) (;W[na];B[ma] (;W[lb];B[oa]C[Ko, Black takes first. Just capturing those two stones is not enough.]TR[kb]TR[kc]) (;W[lc];B[oa]C[Ko, Black takes first. Just capturing those two stones is not enough.]TR[kb]TR[kc])) (;W[lc];B[lb];W[na]C[Gote seki. Black was a bit greedy and pays for it.RIGHT])) (;W[sb];B[sa]C[Ko, Black takes first. You have no big threats, remember.]) (;W[na];B[sa] (;W[oa];B[ma]C[2 stones are not enough.]) (;W[lb];B[oa] (;W[ma];B[pa]C[Just a tiny reduction.]) (;W[lc];B[pa]C[Black gets about 9 points from the corner, levelling out White's gain.]) (;W[pa] (;B[lc] (;W[ra];B[of]C[Err...] (;W[nf];B[qa]C[Ko, Black takes first.]) (;W[sb];B[nf])) (;W[sb];B[oa])) (;B[oa]C[If Black really does not like the ko this reduces the loss anyway.])) (;W[sb];B[lc])) (;W[lc];B[oa] (;W[lb]) (;W[pa];B[lb] (;W[ra];B[of]C[Whoops!] (;W[nf];B[qa]C[Ko, Black takes first.]) (;W[sb];B[nf])) (;W[sb];B[oa])) (;W[sb];B[lb])) (;W[sb];B[pa])) (;W[oa];B[na]) (;W[lb];B[oa]C[Just 2 stones.]) (;W[lc];B[oa]C[Only 2 stones.])) (;W[sb];B[ra] (;W[na];B[qa]) (;W[lb];B[lc];W[na];B[qa]) (;W[lc];B[lb];W[na];B[qa])) (;W[na];B[ra] (;W[lb];B[lc] (;W[oa];B[qa]) (;W[sb])) (;W[lc];B[lb] (;W[oa];B[qa]) (;W[sb]))) (;W[lb];B[oa]C[2 stones is not enough.]) (;W[lc];B[oa]C[2 stones is not enough.]) (;W[oa];B[na]) (;W[qa];B[ra]) (;W[pa];B[ra])) (;W[ra];B[pb]) (;W[pa];B[ra]) (;W[oa];B[pb]) (;W[qa];B[pb]) (;W[lb];B[pb]C[2 stones is not enough.]) (;W[lc];B[pb]C[2 stones is not enough.]) (;W[sb];B[pb])) (;W[pb];B[ob]) (;W[qa];B[ra] (;W[ob];B[nb];W[pb];B[nc]) (;W[pb];B[ob]) (;W[nb];B[ob]) (;W[oa];B[ob]) (;W[pa];B[oa])) (;W[pa] (;B[ob];W[oa];B[na];W[ra];B[sb]) (;B[nb])) (;W[oa];B[ob] (;W[pa]) (;W[na];B[pa] (;W[qa];B[ra]) (;W[ra];B[pb]) (;W[nb];B[ma])) (;W[ra];B[sb];W[pa];B[na]))) (;W[pb];B[qb]) (;W[ob];B[qb]) (;W[nb];B[qb]))) (;W[lc];B[mc]C[2 stones are not enough.]) (;W[lb];B[lc] (;W[qb];B[rb] (;W[nc];B[pb]) (;W[ob];B[pb])) (;W[nc];B[qb])) (;W[nb];B[qb]) (;W[ob];B[qb] (;W[lc];B[lb];W[nc];B[mc]) (;W[nc];B[mc]) (;W[lb];B[lc]) (;W[mc];B[lc]) (;W[nb];B[nc])) (;W[mc];B[nc]))