It is connect 4, not 3.
Look:
|_|_|_|_|_|_|_|
|_|_|_|_|_|_|_|
|_|_|_|_|_|_|_|
|_|_|_|_|_|_|_|
|o|_|_|_|_|_|_|
|o|_|x|x|x|_|_|
You can block one side of the x's, but the other side will still be a win.
If you go on the left of the x's, I go on the right. If you go on the right of the x's, I go on the left. That's why it has previously been referred to as a checkmate. No matter what, it was a win for the x's. |