def disambiguate_san(possibilities)
      move.disambiguation ?
        possibilities.select {|p| self.board.position_for(p).match(move.disambiguation) } :
        possibilities
    end
def disambiguate_san(possibilities)
      move.disambiguation ?
        possibilities.select {|p| self.board.position_for(p).match(move.disambiguation) } :
        possibilities
    end
Try to disambiguate based on the standard algebraic notation.