(;AP[HexGui:0.10.GIT]
C[2021/09/10

Black\: Marietje
White\: Peter

Handicap\: 1

White wins.
]
FF[4]GM[11]PL[B]SZ[11];B[c1]
C[Eric\:

https\://www.hexwiki.net/index.php/Swap_rule#Size_11

is a very good resource for where to put the swap piece, although I disagree with it for d2,e2,f2 and the mirror-images on the bottom.
]
;B[f6];W[d4];B[e4];W[f5](;B[d6]C[Eric\: first g5, see next variation.];
W[d5];B[e5];W[d7];B[e6]C[Eric\:

Again, I would've played g5.];W[h3](;
B[h8]
C[Peter\: Black probably shouldn't have ignored White's threat (to cut off Black at f2). h5 or  c6 or possibly even g6 would have been decent minimaxing responses.

See next variations.]
;W[h9](;B[g9]C[Eric\: better i8, see next variation.];W[f7];B[e7]
C[Eric\:

g6 still reconnects Black to the 1-edge (See the variations for move 12.)
]
;W[f2]C[White makes good on the threat.];B[g3];W[h1];B[j2];W[h6](;B[e8]
C[Peter\: Here i7 would have been a better move. It probably gives Black all ladder escapes along the 11-edge, and it also threatens to cut off White via i4 and j5.

Eric\: g6 still connects to the 1-edge. See next variation.]
;W[i2];B[i4];W[g5];B[i6];W[i5];B[k4]
C[Eric\:

Even passing would win for White now (J3 or use H9 as a ladder escape).

To make the win easy, White could play e3.]
;W[j5];B[k5];W[d3]C[Eric\:

I see White noticed.];B[j6];W[j3];B[i3];
W[j4];B[h4];W[g4];B[resign])(;B[g6]
C[Eric\:

This connects to the 1-edge.];W[h2];B[i4];W[j3];B[i3];W[h5];
B[h4]))(;B[i8]
C[Eric\:


This transposes to

black I8, white H9, black H8,

which I believe is bad for White when (such as here) White does not have a piece nearby in the G8 direction.
]
))(;B[g5]C[Eric\:

This reconnects to the 1-edge, and];W[f2](;B[g3]
C[Eric\:

This is the more-obvious way to keep Black's connection.];
W[h1];B[h2];W[i1];B[j2]C[Eric\:

ladder escape fork])(;B[g2]
C[Eric\:

This is the better way to keep Black's connection.];W[f3];
B[g3]
C[Peter\: this is how Black eventually connects, but Black should play h5 first.]
))(;B[g6]
C[Eric\:

in fact, this too reconnects to the 1-edge.

(After adding the g5 and g6 variations, I now see that this move is already given  by Peter in the comments to h8.)]
;W[f2];B[g2];W[f3];B[h4];W[h5];B[g5]C[Eric\:  g3 or i3]))(;B[g5]
C[Eric\:

I would've played here first, to gain more strength towards the 11-edge.]
;W[h3];B[i4];W[j2];B[i2];W[i3];B[d6]))
