(;AP[HexGui:0.10.GIT]
C[2020/09/11

Black\: Peter
White\: Bian

Black wins.
]FF[4]GM[11]SZ[11]
;B[a5];W[swap-pieces];B[h4];W[f6];B[h7];W[h5];B[i6];W[j4];B[i4];W[i5];
B[g5];W[g6];B[e6];W[e7];B[c8];W[d7];B[c7];W[d6];B[c6](;W[f2]
C[At this point, White could have pushed the ladder and gotten a switchback, see next variation.]
;B[e2];W[f1];B[d4](;W[d3]
C[See next variations for what might have happened if White defended on the other side.]
;B[f3];W[c9];B[d8];W[d10];B[d9];W[c10];B[f8];W[f10];B[f9];W[e11];B[h9];
W[resign])(;W[f3];B[d5];W[f4];B[c2];W[d2];B[b4])(;W[e4];B[e3];W[f3];
B[c2])(;W[g3];B[f3]))(;W[d5]
C[This variation shows how White can get a switchback.

See the next variation for what White would do with d1 instead of e1.]
;B[c5];W[d4];B[c4];W[c3]
C[Notice that the 5x5 triangle in the a1-corner is a ladder generation template for White, which has an escape fork at b10.]
;B[d3];W[f2]C[Now White has the switchback.];B[e3];W[f3];B[e4];W[f4])(;
AE[e1];W[d1];W[d5];B[c5];W[e2];B[d3]
C[White's d1 has a 2nd row ladder generation template, so due to the forking escape at b10 it's already connected. ]
;W[f3];B[e4];W[f4]))
