The floor-to-ceiling windows in the East Room on the seventh floor of Tate Modern offer stunning views of the Thames, St Paul's Cathedral and the City, but on Saturday all eyes were on events inside the room.
After months of anticipation, the climax of The Independent Sudoku Grand Master Championships had arrived. Seventy contestants, whittled down from thousands of postal applications and weeks of regional heats, gathered to vie for a Waterford crystal trophy and a £1,000 cheque.
They had travelled from all over the country; indeed, some had come from even further afield. Molly Butt, 15, and her mother Sarah interrupted their holiday in Biarritz to make the trip. Sarah said: "We had booked our holiday before we knew the final was going to be today but we decided to come because Molly really wanted to do it."
Molly and her family were not the only ones with such a zealous level of commitment. The championship, which had its inaugural contest last year, is a serious business, with 1,200 people taking part in regional heats.
The first half of the field took their seats, the timing equipment was checked and battle commenced.
The semis were not without drama. Last year's champion and this year's favourite, Ed Billig, 24, whizzed through the five puzzles with breathtaking speed but he had made a mistake and so failed to make it to the final. Mr Billig, from Limehouse in east London, had trained for this year's competition using a particular technique. "For the last few weeks I have done puzzles only from The Independent. It gets me in the swing of the style," he said.
After the shortlist of the fastest correct semi-finalists was announced, the 10 qualifiers filed into the room for the final.
A little more than 20 minutes later, the tension was broken by Becky Hewitt who raised her hand to announce she had finished. Her effort was deemed faultless and the 27-year-old primary school teacher from Andover in Hampshire was declared the winner.
She said: "I know I can do them quite quickly but I wasn't at all confident. I didn't know whether I'd made a mistake or not. I can't quite believe it."
It seems youth may be an asset for Sudoku experts. The runner-up was 16-year-old Jeffrey Grant from Weybridge in Surrey, while Molly Butt took third place.
The Independent's marketing director, David Green, gave Ms Hewitt the trophy and cheque. She said: "I am going to celebrate my win with champagne and by not doing Sudoku for a while."Reuse content