Fencer: The game is better when played on a 15x15 board than a 13x13.
About the tournaments: If I`ve understood it correctly, only 1 game is played against each of the other players in the section, and is random who gets to play as white and make the first move. I don`t know about other games but in 5-in-line that doesn`t work because the white has a really huge advantage. In fact, with optimal gameplay (on a 15x15 board or bigger) the one making the first move should win every time.
Of course none of us plays perfect all the time, but still the advantage is too big when 2 really good players are against each other. This problem would be solved if tournament games were 2-game matches, one of each color. Like at IYT.