Clare Balding looks at the role gambling has played in our relationship with sport as she continues her exploration into how Britain made sport and sport made Britain. Betting has played a crucial role in the way games developed, it gave incentive to competition which in turn necessitated clear rules. Establishing who's won and who's lost is crucial but who managed to have a flutter and where was a matter riven with class distinctions as Clare discovers. Reader, Sean Baker Producer: Sara Conkey.