By David Yates One of the most hotly anticipated weeks in the racing calendar gets underway on Tuesday in Cheltenham. Champion’s Day kicks off four days of action, with seven races scheduled for Tuesday. The Champion Hurdle Challenge Trophy is the showpiece event of the opening day, with that race getting underway at 3.30pm. Around 250,000 spectators are expected to travel to the Gloucestershire track for this week’s racing. Irish trainer Willie Mullins is expected to be the big winner at this year’s festival. Mullins has the favourite in many of the 28 races and needs just six winners to beco…