(;AP[HexGui:0.10.GIT]
C[2021/09/16

Black\: Frank
White\: Peter

White wins.
]FF[4]GM[11]
SZ[11];B[a5];W[swap-pieces];B[h4];W[g8];B[i8];W[h9];B[i9];W[h10];B[i10];
W[h6];B[e7]
C[This is an overreach, since Black does not have a 3rd row escape.];
W[d9];B[c8];W[b10];B[e9];W[g6];B[i4]C[Mohex\: White is winning.];W[j5];
B[f7];W[f5];B[e5](;W[f4]
C[Mohex\: losing move. e6 was winning. See next variation.];B[d4];W[d5](
;B[c5]
C[Mohex\: losing move. e4 was winning, see next variation.

White keeps the win.]
;W[d7];B[b7];W[c7];B[resign])(;B[e4];W[e6];B[c7];W[d6];B[b6];W[c5];B[a5]
C[OK, this is a trick I did not see. The 3rd-to-5th row switchback does not work if d4 is occupied and Black yields at this exact moment.]
;W[b5];B[a6];W[b3];B[b4];W[d3];B[c4];W[f3];B[e3];W[f2];B[e2];W[f1];B[c2]
))(;W[e6];B[c7];W[d6];B[c6];W[d5];B[c5];W[d4];B[c4];W[c3]
C[Note\: in the presence of a foldback threat, a5 works as a 4-to-6 switchback.]
;B[d3];W[f2];B[e3];W[f3]))
