[DDRickyDD]

Why is playing at home generally seen as an advantage? What difference does it make?

[King Gizzard]

Because you have more fans which will make more noise to hopefully encourage the players. Plus the away team in some cases will have to travel a considerable distance to get to the stadium and there will be factors to do with a worse conditions in an away dressing room in comparison to when you play at home.

[DDRickyDD]

I found this helpfull site. http://en.wikipedia.org/wiki/Home_advantage