Player Positioning in the Four-Legged League

As RoboCup continues its march towards the day when robots play soccer against people, the focus of researchers' efforts is slowly shifting from low-level systems (vision, motion, self-localization, etc) to high-level systems such as strategy and cooperation. In the Four-Legged League (recently renamed to the Standard Platform League), teams are still struggling with this transition. While the level of play has consistently risen each year, teams continue to remain focused on low-level tasks. Surprisingly few of the 24 Four-Legged teams that competed at RoboCup 2007 were able to self-position at the beginning of the game, despite penalties incurred for not doing so. Things considered to be standard in `real' soccer --- positioning, passing, overall strategies --- are still, after 10 years of research, far from a given within the league, and are arguably in their infancy compared to other RoboCup leagues (Small-Sized, Mid-Sized, Simulation). Conversely, for the top teams, many of these low-level systems have been pushed far enough that there is little to be gained in soccer performance from further low-level system work. In this paper we present a robust and successful player positioning system for the Four-Legged League.