Willemiens sandboxed problem (13491) was interesting, also from the other side's perspective. Try to live with points or protect the corner in sente, if possible.
(;AW[da]AB[ca]AB[db]AB[cc]AB[cd]AB[bd]AB[ce]AB[bf]AB[af]AW[ag]AW[bg]AW[cf]AW[de]AW[dd]AW[eb]AB[dc]AW[ec]AW[ea]AW[cg]AW[ef]AW[bb]MA[bb]C[White just played the marked stone, expecting a gote seki. However, White would be more than happy to kill, get a ko for life or a nice reduction in sente as a bonus...]AP[goproblems]
(;B[cb];W[ae]
(;B[be];W[ac]
(;B[ad];W[ba]
(;B[ab];W[aa]C[Sente seki. The 2 captured stones cancel each other out for points.RIGHT])
(;B[bc];W[ae])
(;B[aa]C[Gote seki. White is in no hurry to capture A19.]))
(;B[bc];W[ba]
(;B[ad];W[ae])
(;B[ab];W[ad])
(;B[aa];W[ad]))
(;B[ba];W[ad]
(;B[bc];W[aa])
(;B[ab];W[aa]C[Ko, White takes first. Also Black risks much more than White.])
(;B[aa]C[Gote seki.]))
(;B[aa];W[ad]
(;B[ba]C[Gote seki.])
(;B[bc];W[ba])
(;B[ab];W[ba]))
(;B[ab]
(;W[bc]
(;B[ad];W[aa]C[Sente seki.RIGHT])
(;B[ba];W[aa]C[Ko, White takes first])
(;B[aa];W[ba]))
(;W[aa];B[ad];W[bc]C[Sente seki.RIGHT])
(;W[ba];B[ad];W[aa]C[Sente seki. The 2 captured stones cancel each other out for points.RIGHT])))
(;B[ad];W[be]
(;B[ab];W[ba])
(;B[ba];W[ab])
(;B[bc];W[ba]))
(;B[ac];W[be])
(;B[bc];W[be]
(;B[ab];W[ba]
(;B[ad];W[ac])
(;B[aa];W[ad]))
(;B[ad];W[ba])
(;B[ba];W[ab]))
(;B[ba];W[ac]
(;B[ab];W[aa]C[If Black seeks a ko threat next that means this is a ko for life which isn't good enough. But Black may try to play on locally.]
(;B[ad];W[be];B[ab]C[Ko for life. Even if Black wins that is just +1 point for double gote.])
(;B[be];W[ad];B[ab]C[Ko for life. Even if Black wins that is just +9 points for double gote.])
(;B[bc];W[be];B[ab]C[White has 5 points, Black 4 or 6 depending on who takes the last 2 point gote move. This is essentially equal to a gote seki. The solution is a sente seki.]))
(;B[bc];W[be]
(;B[ad];W[aa])
(;B[ab]C[Gote, 3 points to Black, 4 points to White. A16 remains as a 2 point gote move for both sides.]))
(;B[ad];W[be]
(;B[bc];W[aa])
(;B[ab];W[aa]C[Ko, White takes first.]))
(;B[be];W[ad]
(;B[bc];W[aa])
(;B[ab];W[aa]C[Ko, White takes first. Also Black risks much more than White.])
(;B[aa]C[Gote seki.]))
(;B[aa];W[be]))
(;B[ab];W[be]
(;B[ba]C[Gote; White has 4 points, Black at least 3. Next, Black can get 2 additional points in gote by playing A16, or White can prevent that (in gote) by playing A17-bB17-wA16.])
(;B[ad];W[ba])
(;B[ac];W[ba])
(;B[bc];W[ba]
(;B[ad];W[ac])
(;B[aa];W[ad])))
(;B[aa];W[be]))
(;B[ae];W[ac]
(;B[cb];W[ad];B[be];W[ba])
(;B[bc];W[cb])
(;B[ba];W[cb])
(;B[ad];W[cb])
(;B[ab];W[aa]
(;B[ad];W[cb])
(;B[cb];W[ad])
(;B[bc];W[cb])
(;B[ba];W[cb])
(;B[be];W[cb])))
(;B[ad];W[cb])
(;B[ac];W[cb]
(;B[ae];W[bc])
(;B[bc];W[ae])
(;B[ba];W[aa]
(;B[ca];W[ae])
(;B[ab];W[ae]))
(;B[ab];W[ae]))
(;B[bc];W[cb]
(;B[ae];W[ac])
(;B[ab];W[ba]
(;B[ae];W[ac])
(;B[ac];W[ae]))
(;B[ac];W[ae]))
(;B[ba];W[cb])
(;B[ab];W[cb]
(;B[ae];W[ac]
(;B[ad];W[aa])
(;B[bc];W[aa])
(;B[ba];W[aa]))
(;B[bc];W[ba]
(;B[ae];W[ac])
(;B[ac];W[ae]))
(;B[ac];W[ae])
(;B[ba];W[aa]))
(;B[be];W[cb])
(;B[aa];W[cb]))