According to the song, 'Old Christmas comes but once a year' but, for one anonymous Sky Bet punter, the festive season started several weeks early in 2017. On December 7 that year, the unnamed individual staked £2.30 each-way on a five-fold accumulator on National Hunt racing at Leicester and Wincanton. Four of his five selections – Arthington (3/1), Vocaliser (18/1), Lagavara (9/2) and Dontmindboys (4/1) – were at…