Rob Eastaway is a writer, speaker and consultant. His books include the bestselling What is a Googly? (9781861056290) and Why Do Buses Come In Threes? (9781861058621). He jointly devised the system now used to officially rank international cricketers and lives in London, where he is a keen weekend cricketer and occasional golfer. David Wells was the British under-21 chess champion in 1961, and for many years he was puzzle editor of Games & Puzzles magazine. His books include The Penguin Dictionary of Curious and Interesting Puzzles.