The main thing are the signs characters. The pentagonal shapes are nice but secondary, because the orientation of the characters shows the owners.
The above example is exactly what I think about.
[Edited by playBunny to make the link work. it gives a list of recorded matches. Then click any of the Java links to see the board and play through the game.]
(esconder) Se passar com o rato no ícone de nível de inscrição de um jogador, surge um pequeno texto com os seus detalhes. (pauloaguia) (mostrar todas as dicas)