Problem 16283 goproblems.com


Author	BobTheJoe	Created	2012-07-21
Difficulty	12 kyu (history)	Source	Basic Techniques of Go by Haruyama 8 dan and Nagahara 6 dan
AVG solve time	62 sec	Stars	4.6 (10 votes)
User attempts	1181 / 3279	Collections	N/A
Genre	tesuji ⓒ	Your attempts	N/A
Similar problems
Created	2012-07-21
Source	Basic Techniques of Go by Haruyama 8 dan and Nagahara 6 dan
Stars	4.6 (10 votes)
Collections	N/A
Your attempts	N/A

(;AB[bc]AB[cd]AB[ce]AB[dd]AB[ed]AB[df]AB[dg]AB[dh]AB[ci]AB[dj]AB[bj]AB[bk]AB[bf]AW[be]AW[bd]AW[cc]AW[bb]AW[de]AW[cf]AW[ch]AW[cg]AW[bh]AW[bi]TR[cf]TR[cg]TR[ch]TR[bh]TR[bi]C[Black has a tesuji on the side to capture the marked stones. Can you find it? (has been edited slightly to avoid complex variations)]AW[cb]AP[goproblems] (;B[ag];W[bg] (;B[af];W[ac] (;B[ai];W[ae];B[ah]C[Correct! The kosumi tesuji!RIGHT]) (;B[ah];W[ae];B[ai]C[Correct! The kosumi tesuji!RIGHT]) (;B[ae];W[ad] (;B[ai];W[ah]) (;B[ah];W[ai])) (;B[ad];W[ae] (;B[ai];W[ah]) (;B[ah];W[ai]))) (;B[ae];W[af]C[Ko. Black can do better.]) (;B[ah];W[af] (;B[ai];W[aj]) (;B[aj];W[ai])) (;B[ai];W[af] (;B[ah];W[aj]) (;B[aj];W[ah])) (;B[ad];W[af])) (;B[ai];W[af] (;B[ah];W[bg] (;B[aj];W[ag]) (;B[ag];W[aj]) (;B[ac];W[ag];B[aj])) (;B[bg];W[ag]) (;B[ag];W[bg] (;B[ah]) (;B[aj];W[ah])) (;B[ad];W[ac] (;B[ah];W[bg] (;B[aj];W[ag]) (;B[ag];W[aj])) (;B[ag];W[bg] (;B[ah];W[aj]) (;B[aj];W[ah]))) (;B[aj];W[ah])) (;B[ae];W[ac] (;B[ag];W[bg] (;B[ai];W[af]C[Ko. Black can capture unconditioonally.]) (;B[ah];W[af]C[Ko. Black can capture unconditionally.]) (;B[af];W[ad] (;B[ai];W[ah]) (;B[ah];W[ai])) (;B[ad];W[af])) (;B[bg];W[ag] (;B[af];W[ad]) (;B[ad];W[af]) (;B[ai];W[af]) (;B[ah];W[ai];B[aj];W[af])) (;B[ai];W[bg] (;B[ag];W[af]C[Ko. Black can capture unconditioonally.]) (;B[ah];W[af] (;B[aj];W[bf]) (;B[ag];W[aj])) (;B[af];W[ad] (;B[ah];W[ag]) (;B[ag];W[ah])) (;B[ad];W[af])) (;B[ah];W[bg] (;B[ag];W[af]C[Ko. Black can capture unconditionally.]) (;B[ai];W[af] (;B[aj];W[bf]) (;B[ag];W[aj])) (;B[af];W[ad] (;B[ai];W[ag]) (;B[ag];W[ai]))) (;B[af];W[ag] (;B[ai];W[ad]) (;B[ah];W[ai] (;B[aj]C[Black can't push at b13]) (;B[bg];W[ad]) (;B[ad];W[bg])) (;B[bg];W[ad]) (;B[ad];W[bg])) (;B[ad];W[af])) (;B[bg];W[ag] (;B[ai];W[af]) (;B[ah];W[ai] (;B[aj];W[af]) (;B[af];W[ae]) (;B[ae];W[af]) (;B[ad];W[ac];B[aj];W[af]) (;B[ac];W[cb] (;B[ae];W[af]) (;B[ad];W[af]) (;B[aj];W[af]))) (;B[af];W[ae]) (;B[ad];W[ac] (;B[ai];W[af]) (;B[ah];W[af])) (;B[ae];W[ac] (;B[af];W[ad]) (;B[ad];W[af]) (;B[ai];W[af]) (;B[ah];W[ai];B[aj];W[af])) (;B[ac];W[ab] (;B[ae];W[ad]) (;B[ad];W[ae]) (;B[af];W[ae]))) (;B[af];W[ag] (;B[ae];W[ac] (;B[ai];W[ad]) (;B[ah];W[ai] (;B[aj]C[Black can't push at b13]) (;B[bg];W[ad]) (;B[ad];W[bg])) (;B[bg]) (;B[ad];W[bg])) (;B[ad];W[ac];B[ae];W[bg]) (;B[bg];W[ae]) (;B[ai];W[ac] (;B[ah];W[aj]) (;B[aj];W[ae];B[ah];W[bg]) (;B[bg];W[ae]) (;B[ae];W[ad])) (;B[ah];W[ai]) (;B[ac];W[bg] (;B[ai];W[ae]) (;B[ah];W[ai] (;B[aj];W[ae]) (;B[ae];W[ad]) (;B[ad];W[ae])) (;B[ae];W[ad]) (;B[ad];W[ae]) (;B[ab];W[cb] (;B[ae];W[ad]) (;B[ad];W[ae]) (;B[ai];W[ae]) (;B[ah];W[ai];B[aj];W[ae])))) (;B[ad];W[ac] (;B[ag];W[bg] (;B[ai];W[af] (;B[ah]) (;B[aj];W[ah])) (;B[ah];W[af] (;B[aj];W[ai]) (;B[ai];W[aj])) (;B[af];W[ae] (;B[ai];W[ah]) (;B[ah];W[ai])) (;B[ae];W[af]) (;B[aj];W[af] (;B[ah];W[ai]) (;B[ai];W[ah]))) (;B[ae];W[af]) (;B[af];W[ag];B[ae]) (;B[bg];W[ag] (;B[ai];W[af]) (;B[ah];W[af])) (;B[ai] (;W[ag];B[aj];W[af];B[ah];W[bg]) (;W[bg];B[ah];W[af] (;B[aj];W[ag]) (;B[ag];W[aj]))) (;B[ah];W[ag] (;B[aj];W[ai]) (;B[ai];W[aj]) (;B[af];W[ai] (;B[aj];W[ae]) (;B[bg];W[ae]) (;B[ae];W[bg])) (;B[bg];W[af]))) (;B[ah];W[af] (;B[ac];W[ab] (;B[ai];W[bg] (;B[aj];W[ag]) (;B[ag];W[aj]) (;B[ad];W[ae])) (;B[ad];W[ae]) (;B[ae];W[ad]) (;B[bg];W[ag]) (;B[ag];W[bg] (;B[ai];W[aj]) (;B[aj];W[ai]) (;B[ad];W[ae]) (;B[ae];W[ad])) (;B[aj];W[bg] (;B[ai];W[ag]) (;B[ag];W[ai]) (;B[ad];W[ai]) (;B[ae];W[ai]))) (;B[ag];W[bg] (;B[ai];W[aj]) (;B[aj];W[ai])) (;B[bg];W[ag]) (;B[ai];W[bg] (;B[aj];W[ag]) (;B[ag]) (;B[ac];W[ag];B[aj])) (;B[ae];W[bg] (;B[ag];W[ai]) (;B[aj];W[ai]) (;B[ai];W[ad];B[aj];W[ag])) (;B[ad];W[ac] (;B[ai];W[bg] (;B[aj];W[ag]) (;B[ag];W[aj])) (;B[bg];W[ag]) (;B[ag];W[bg] (;B[ai];W[aj]) (;B[aj];W[ai])) (;B[aj];W[bg];B[ai];W[ag])) (;B[aj];W[bg] (;B[ai];W[ag]) (;B[ag];W[ai]))) (;B[ac];W[af] (;B[cb] (;W[ab];B[dc]) (;W[bg];B[dc];W[ad])) (;B[bg];W[ag]) (;B[ai];W[bg];B[ah];W[ag];B[aj]) (;B[ah];W[ab] (;B[ai];W[bg] (;B[aj];W[ag]) (;B[ag];W[aj]) (;B[ad];W[ae])) (;B[ad];W[ae]) (;B[ae];W[ad]) (;B[bg];W[ag]) (;B[ag];W[bg] (;B[ai]) (;B[aj];W[ai]) (;B[ad];W[ae]) (;B[ae];W[ad])) (;B[aj];W[bg] (;B[ai]) (;B[ag]) (;B[ad];W[ai]) (;B[ae];W[ai]))) (;B[ae];W[bg] (;B[ad];W[ab]) (;B[ab];W[ad])) (;B[ag];W[bg])))