I recently started a match on a 25x25 board and I was wondering how this would effect the opening.
I’ve seen extreme size games before but they just came off as longer 19x19 games to me.
So I’d like to know if there’s some tactics or meta already in place for this kind of format.
The meta for large board sizes is pretty much non-existent. Professional players aren’t interested in it (I’m not aware of any game records), and many amateurs don’t have the attention span required to finish the games, which can take over 2 hours at a brisk pace.
That’s not to say large boards aren’t interesting. You might consider making a group for it to gauge interest and find like-minded opponents.