Well that's true, but the Kong wang aspect is said to be more important than any other. Even when Other is weak, if the team that Self represents is Empty he could not have scored 2 goals as he did (2:0 result).
See if I can find other examples on this subject....
As far as sports go, lately I have some doubts on the whole approach... Jack has example of it and he has read one tennis match in old forums, yet I haven't seen him using it for a match that is still not played, so no idea how reliable that is.
Technically, line strength can mean many things, but logically it would show what team is more capable, prepared etc.
Everyone that has watched sport, should be aware, that the better team, doesn't always win...
Im QMDJ, sometimes for football matches(soccer for US people), instead of looking only at the teams, there is representation of the ball for example(yang metal, seems to be one of those, as its round and moving fast, also it fits to the images of yang metal there, as something attacking the Jia, while in the game, attacking the "doors") and we can try to see where it will end up and stuff like that.
But watching only the lines, I have doubts will work(I haven't tried sports, lately a lot, but back when I was, was definitly not working with only looking at the lines).