This is gonna get ugly quick... so a Thought Experiment for you...
Let's assume two things first: That everybody is human, and humans are inherently biased against various things. It's practically impossible to remove all bias of gender because it is impossible to be naturally male and naturally female in the same lifetime*. That out of the way, here's the experiment:
Make a eSports team composed randomly of male and female members, give them androgynous aliases and seclude them from contact with other players outside of matches and scrims (no pugs or pubs!). Since you cannot determine gender by the usual methods of visual/audio confirmation, you only have their gameplay to go off of. Would you, after observing this team for a full season, be able to correctly determine the gender of each player?
* -