There are several openings which are worthless because of symmetry rules: orange can simply mirror every move of violet’s & produce a tie (or, if violet screws up, a win). W to the centre or Z5 to the centre on move 1 are examples of mirrorable openings. The only way for violet to break the mirror is to be able to force an assymetry at the centre of the board (e.g. by occupying 3 out of 4 of the central squares).
Both of the following are what I call quasi-mirrors: it is not impossible for violet to break the mirror at this stage, but there seems to be no strong move available to violet that would break the mirror. — In the case of the N opening, the only available mirror-breaker is L5 in the centre (violet need not play this on move 2, but needs to keep the space open for the L5 move unless orange stops mirroring first). In the case of the X opening, the obvious move is F into the centre (occupying 3 out of 4 squares), but this seems weak.