(;AP[HexGui:0.10.GIT]
C[2021/04/23

Black\: Frank
White\: Peter

White wins.
]FF[4]GM[11]PL[B]
SZ[11];B[a6];W[swap-pieces];B[f6];W[h4];B[e5];W[e6];B[f5];W[f7];B[e7];
W[d9];B[g8];W[d10](;B[f8];W[g10];B[g9]
C[This move leaves White with a 3rd row ladder escape. But it's unclear whether Black could have prevented that. f10 would have given White a switchback, and both h8 and h9 would have given White an escape.


Eric\:

Black should've played E10 or H9 instead.  After E10, G10 gives a switchback for height-2 ladders, but I don't think it does anything more for White.]
(;W[e8]C[Eric\: see next variation for a comment.];B[h6]
C[Eric\:

I think I would not have noticed this on my own, but based on the comment I saw left in chat and the highlighted area as I came to this board, I infer that White has enough room in the A1 corner for the A6 switchback ^_^.

If that's correct, then this is now a forced win for White.

As Peter just pointed out to me, there's even enough room for Tom's move\: D3 might connect to H4 instead of D6.
]
;W[g6];B[c9];W[b11];B[a11](;W[b10]
C[Switchback variation. See next variation for using Tom's move.];B[a10]
;W[b9];B[a9];W[b8];B[a8];W[b7];B[a7];W[c3]
C[White plays the A6 switchback\: https\://www.hexwiki.net/index.php/Switchback#A6_switchback]
(;B[b5]
C[Now White gets the switchback without using f1. See next variation for b6.]
;W[b6];B[a6];W[d4];B[h5];W[g5];B[j3];W[i2];B[h3];W[i3];B[k1];W[i4];B[j4]
;W[i5];B[j5];W[i6];B[j6];W[i7];B[j7];W[i9];B[resign])(;B[b6];W[d5];B[c4]
;W[e3];B[d3];W[e1];B[b2];W[c2];B[a4];W[b5]))(;W[d8]
C[Tom's move variation.];B[c8];W[d7];B[c7];W[d6];B[c6];W[b10];B[a10];
W[b9];B[a9];W[b8];B[a8];W[b7];B[a7];W[c4];B[b5];W[d3];B[c5];W[e4];B[d5];
W[g3]))(;W[h9]
C[Eric\:

This move makes G9 completely useless. (The F10 region would be whoever-moves-connects with or without G9.)]
))(;B[h7]C[Eric\:

This looks good for Black.];W[f9]
C[Eric\:

If White responds here,];B[e10]
C[Eric\:

then Black can play this.]))
