samwise: I never claimed to be good at pente, no did i claim to know the game well. Even so, i agree with you in regards to the opening restriction. The advantage is quite obvious without it for the first player. But as Dmitri has confirmed, very few games would be confined by the edges if played on a 13x13 board. And especially against new players, the edge will not be a factor. So besides it not being invented that way, none of you have said why a 13x13 board is "wrong".
Dmitri: I do trust players with experience, and i believe you, samwise and Gary are all very experienced. If any of you can come up with a good reason why a 13x13 board is "wrong" (besides it not being invented that way) for casual competition, i will gladly support it. But for now, i see nothing wrong with playing on a 13x13 board.