SAS FENCES

Cul-de-sac with 2 piece-moves/turn, and L-shaped walls allowed. Each player has one grenade, which may be played at the start of a turn to blast an unfillable hole in any unit of wall; and this uses the placement power for that turn.

Here is a match where the South player (ie, which must go to the north edge) was forced to close himself.

       S           N                  S           N
1.  -N  EGd     SE  FHi        11. WN  Je4    gJKf SS
2.  NW  GId     EE  Ei4        12. WN  JLi    SW  Hik
3.  SW  Jc2     WS  Dj4        13. SN  Ii2    NW  Hh3
4.  SW  Ic3     WW  Ck4        14. SN  Hh2    EE  Fh4!
5.  EE  Fg4     EN  Fk3        15. resign
6.  WN  Gb4     EE  Iac        16.
7.  EE  Fik     NE  Gik        17.
8.  SE  Kbd     SS  Jc4        18.
9.  EN  JLf     SW  Ij3        19.
10  SE  HJe     ES  IKk

Final Position:

  A   B   C   D   E   F   G   H   I   J   K   L
a +-------------------------------------------+ a
  |                               |           |
b |   +   +   +   +   +   ,---+   |   +   +   | b
  |                       |       |   |   |   |
c |   +   +   +   +   ,---+   +---.---;---|   | c
  |                   |           |   |   |   |
d |   +   +   +   +-------+-------+   +   +   | d
  |                                           |
e |   +   +   +   +   +   +   +-------+---+   | e
  |                                   |       |
f |   +   +   +   +   +   +   +   +   >   <---| f
  |                                           |
g |   +   +   +   +   +   +   +   +   +   +   | g
  |                           |         N     |
h |   +   +   +   +   ,---+---+---+   +   +   | h
  |                   |       |   |           |
i |   +   +   +   ,---+-------+   +---+-------| i
  |               |   |   | S |               |
j |   +   +   ,---+   |   |   |---.   +   +   | j
  |           |       |   |   |   |           |
k |   +   .---+   +---.   +   +   +-------+   | k
  |       |           |                       |
l +-------------------------------------------+ l
  A   B   C   D   E   F   G   H   I   J   K   L

In this position, South only route of escape is between Ii and Li, since everything else has double walls and he has only one grenade.