All the things you never realised you wanted to know about snooker - such as why a straight shot can be rolling in both directions, and why playing from one end of the table is different from playing from the other. Steve Davis , the World Champion, takes on Peter Lawrenson , a scientist. With the help of slow-motion cameras, specially marked balls, an executive toy, some coins, a computer and even an electric drill, their unusual contest offers some unexpected revelations.