While it is true that will always result in a winning line, it’s not true that it is the only way to force a win. Half of their moves will allow you to play adjacent to you starting corner towards an open corner and still force a win, as long as their first play isn’t the opposite corner or any of its 3 adjacent spaces. In fact, if they start in one of the adjacent sides or non-opposite corners, you have 3 winning moves. If they start on a side, you can take either the open, non-opposite corner, the side leading to that corner, or the middle. If they start in a non-opposite corner, you can take the first two moves above, or the opposite corner.
This was exactly the explaination from the old Exoanded Universe/Legends in Star Wars. The most sophisticated piece of any fighter was their EWAR suite. Otherwise fighters would be wiped out from well beyond visual ramge by capital ships’ point defense systems, and it’s why they needed to get so close so their sensors could power through the jamming to get missile locks on other fighters.