Short corners.
I've never got this fully. You have the chance of a free cross into the area. Why do so many teams give up this chance? I see SO many teams simply pass it short, run about a bit and either lose the ball or pass it back to the half way line. Top teams even do it. It's the equivalent of a winger getting into a good position behind the defence ready to cross then turning round and passing it back to the centre backs. I DON'T GET IT it's infuriating and it's fucking stupid.
This, of course, doesn't apply to teams who obviously have a successful, planned short corner routine.