Playing the game, it seems like Team Github doesn't actually know the rules of the game, and are just playing optimally as if for normal tic-tac-toe. They continually force Team Twitter into the middle area (by continually playing in the middle square of each area), allowing the most dominant meta area to be given up. Looking at the numbers of people that are choosing each square, it doesn't seem like it has anything to do with the number of people on each team. Literally every single person on Team Github chose the same squares in the most crucial mistakes.