[Ieadin]

G48> Entering GAME PIECES onto the field - Only the HUMAN PLAYERS may enter a RINGER
or SPOILER onto the field, either by attempting to throw it to a ROBOT or onto the RACK,
passing it through the CHUTE to a ROBOT, or passing it through the CHUTE for pickup by a
ROBOT. If GAME PIECES are thrown, they must be thrown over the top of the Alliance
Station Wall, and may not be thrown around the side of the Alliance Station Wall. Violations
of this rule will result in a 10-point penalty per GAME PIECE entered onto the field.

I guess this means that if you want you human player to throw ringers onto the rack he would need to do that over the wall.