I WONDER how detective pairings come about in real-life? I don’t imagine human resources engage in an elaborate matching service. Officers just have to take who they get. Television is different. On television, it is practically the law that opposites should attract. It has been the same since the original and best match, that of Sherlock Holmes and Dr Watson. Sherlock was a flash of lightning, Watson was a stick in the mud; Sherlock was brilliant but mercurial; Dr Watson was a steady as he goes type. To put it another way, the Donny and Marie Osmond way, it is best if one detective is a little bit country and the other is a little bit rock and roll. If nothing else it helps the viewer distinguish between them and generates friction, adding to the drama.