2004 - FIRST Frenzy - Raising the Bar Two mobile goals, four feet in height, were also on the field, originally found on either side of the center. On the sides of the field midway between each alliance station, there were two ball tee stations, each containing two tees with Bonus Balls on them. On the top of each tee's frame was an infrared beacon that robots with infrared sensors could detect. A line of white tape led from the robots' starting position to the ball tees. On top of each alliance station was a container with eighteen Small Balls in it at the beginning of the match that would release the Small Balls onto the field at the appropriate time. In each corner of the playing field there was a two-foot-wide gap in the wall separating the field from the alliance stations (known as the Ball Chute) so that robots could pass Small Balls to the human players. Each alliance stations contained areas for two teams. Each team area contained a Ball Corral in front of their Ball Chute with two crossbars on the front and sides. At the beginning of each match, three Small Balls were placed on the front crossbar for each team.