[ThatHubrexGuy]

Depends on the field. Assuming "standard soccer rules" includes field specifications, I would say humans. And that's not only because the size of the field would give human players, who are more agile and responsive and advantage, but also because soccer is played on grass, a surface that I can't imagine many robots being able to navigate on. However, I could imagine some robots being able to beat human players on, say, a Breakaway-size field with a carpeted surface. That is, after all, the terrain and field size robots were designed for.