game theory says the seer wins every fight because one side is getting perfect information about what the other is going to do while the other side can only guess and base his actions on what he sees. the only chance for the Sparker to win is if he or she can surprise the seer by splitting on the first pass (attack) and the seer is surprised by this and doesn't react fast enough. i do agree that it also depends on skill level if both fighters are low skill the seer should win 9/10 times while at higher skill levels i would say the Sparker would win 6/10 times.
this is just what i think based of what i know (which isn't as much as i would like) so if anyone has any comment or my info/reasoning is wrong feel free to tell me.