But even the most dedicated Sudoku-solver might have never spotted this secret pattern. Mathematicians have uncovered a powerful pattern known as the 'Phistomefel Ring' - and it's hidden in every ...

Put your brain to the test with a brand a new sudoku puzzle here on Stylist every day. Welcome to Stylist’s daily sudoku challenge: the game that promotes critical thinking and problem solving.

Play our daily hard sudoku here. Plus, you can let us know what you think of the puzzles by emailing at hey@metro.co.uk. We look forward to hearing from you.

Play our daily hard sudoku here. Plus, you can let us know what you think of the puzzles by emailing at hey@metro.co.uk. We look forward to hearing from you.