Why does Jimmy,
pull everyone back for corners,
It's generally considered the best way to defend corners and ironically can be a more attacking tactic. Statistics show that the more players in the box the harder it is to score which is why they like to pack the penalty area when defending corners. It also sucks up the opponents defenders giving more space for a potential breakaway. You would be more likely to leave a player up the pitch if you want him to hold up play if it gets to him. There's very little likelihood of him actually scoring a goal on his own.