Australia’s greatest footy rivalries used to be strictly intra-code affairs – obvious examples being league’s State of Origin, union’s Bledisloe, the Montague/Capulet feuds between Carlton and Collingwood (or, come to that, Hawthorn and Geelong or North Melbourne and Essendon). But since rugby union turned professional much of the snobbery which separated it from rugby league has disappeared, and in addition to competing for ratings and ticket sales the two codes now compete against each other for talent, and players deemed good enough to play both at the elite level are faced with a dilemma rather more consequential than whether to...