You need rare courage to be the rock at the rear. So any butter-fingered shrinking violets should step away now – full-backs need to spring like a hare and catch the ball unerringly in the face of dastardly challengers. Positional awareness is a given – you have a lot of ground to cover out there – and a solid boot is required to clear your lines. If you can also kick goals like Leigh Halfpenny, consider yourself hired. The best exponents of fullback play will pose endless threats as a runner, linking with their fellow backs or bursting into the line to create an overlap.