Author of a wide range of brain-training and puzzle books for both children and adults, including best-selling Ordnance Survey Puzzle Book, Brain Games for Clever Kids, The Kids' Book of Crosswords and The Mammoth Book of New Sudoku, plus many dot-to-dot, maze and activity books.
He is also the creator of online brain training site www. BrainedUp.com, and runs the daily puzzle website www. PuzzleMix.com.
He gained his Ph. D from Cambridge University.