SESQUY

On each turn, each player drops a friendly stone on an empty cell and then
(optionally) moves another friendly stone to an adjacent empty cell.

Sample game:
                                  XX            OO (swapped)
: abcdefghijklmnopqrstuvwxy  ================================
|             .              1. l6   ----       m11  ----
|            . .             2. j10  l6 m7      k9   m11 l10
|           . . .            3. j8   j10 i9     h10  k9  j10  
|          . . . .           4. o9   j8 l8      o11  l10 m11
|         . . . . .          5. r10  l8 m9      r12  j10 k11
|        . . . x . .         6. u11  i9 j10     t12  h10 i11
|       . . . . . . x        7. v12  o9 p10     t10  t12 s11
|      . . . . . o O o       8. p12  r10 q11    o9   o11 n10
|     . . . . x o . x ,      9. s9   p10r10     p8   t10 u9
|    . . . x . o . x . .    10. s7   m7n6       r8   u9  t8
|   . . . o o o . x o x .   11. X resigns
|  . . . . . . . x o . x .  12.
| . . . . . . . . . . . . . 13.
: abcdefghijklmnopqrstuvwxy 14.