Premise: The 2007 Grand National (known as the John Smith's Grand National for sponsorship reasons) was the 160th official annual running of the world-famous Grand National steeplechase which took place at Aintree Racecourse near Liverpool, England, on 14 April 2007 and attracted the maximum permitted field of forty competitors for a total prize money of £700,000 including £399,140 to the winner.
Hypothesis: The Grand National steeplechase entry fees had to be paid by April 1, 2007