Sloths

William Hartston is a Cambridge-educated mathematician and industrial psychologist. Between 1962 and 1987 he played chess competitively, becoming an international master and winning the British chess championship in 1973 and 1975. He runs competitions in creative thinking at the annual Mind Sports Olympiad, writes the off-beat Beachcomber column for the Daily Express. , where he is also the opera critic, and is the author of several books on chess, numbers, humour and trivia, including The Things That Nobody Knows. and Even More Things That Nobody Knows. He is also one of the viewers on Channel 4's Gogglebox.