A player kicks the ball, the goalkeeper dives, the crowd… is puzzled.
Sometimes the ball misses (or of course goes in) by such a small amount that no one can tell what happened for a few moments.
It seems to me that although this slight delay in understanding isn’t exactly monumentally important,
if there were a cheap improvement, it would be worth trying.
The aim is to make it easier to see the ball moving across the side of the goal. The simplest thing to try would be to extend the goal posts down the back and sides of the net, so that you would have two chances to spot the ball going past a bar (the net is effectively transparrent). I think this would help from some TV camera angles, and possibly help some of the crowd.
Not entirely earth shaking, but simple, which means it could possibly work.