Y using the Lovely mutator

LOVELY modifier: along with one's own stone one must play an opponent
===============  stone as (euclidean) close as possible to one's own

                             ooo      xxx
                            ---------------
          .             1.  k7,j6    l6,k5
         . .            2.  n8,o9    i7,h6
        . . .           3.  j10,i11  g7,f6
       . . . .          4.  g9,f10   h10,g11
      . . o . .         5.  m9,n10   m11,o11
     o o x x . .        6.  k11,l10  k9,l8
    . x x o . . .       7.  resign
   . . . . o o . .      8.
  . . o . x o x . .     9.
 . . x x o x x . . .   10.
. . . o x o x o . . .  11.
abcdefghijklmnopqrstu

This mutator is based on Vincent Everaert's In Love Gomoku. One problem, imho, with In-Love mutator is that it permits tabu cells, ie, isolated cells where it's not legal to drop pieces. This tabu cells can produce much more drawish games (which seems the case with Gomoku). Using a closer cell to place the enemy stone, tabu cells are eliminated while still allowing all the tactical possibilities of the original mutator.