To the pirates vs ninja battle (sorry, ive been away for a while) we do plan on doing that, but we werent sure how many pirates would be wanting to play, we were going to have the good vs evil match because everyone can play in that, and then we were going to do some other matches when we knew what cosplayers we'd have
And one of our goup is making hats that will have the peices names on them in either black or white, and i did consider the chess board!!!!!! we may bring one for the leader of each side to see the full board.
As for claiming spots, i am only claiming my position as ref as it doesnt really change the board, and as the organisers Leaders Cosplay are simply claiming the spots they want in advance. Really, the peices will be decided at the event!