Prospective BBGs are first nominated by their school headteacher, to be considered for selection. To be selected, a candidate must pass written tests on the rules of tennis, and pass fitness, mobility and other suitability tests, against initial preliminary instruction material. Successful candidates then commence a training phase, starting in February, in which the final BBGs are chosen through continual assessment. As of 2008, this training intake was 600. The training includes weekly sessions of physical, procedural and theoretical instruction, to ensure that the BBGs are fast, alert, self-confident and adaptable to situations. As of 2011, early training occurs at the Wimbledon All England Lawn Tennis Club Covered Courts, to the side of the Grounds, and then moves to outside courts (8, 9, 10) the week before the Championships to ensure that BBGs gain a feel of the grass court.