The Grand National is by far the harshest, most controversial race in the UK’s National Hunt racing calendar. The jumps are tougher, the field is larger and the stakes are higher at Aintree’s showpiece event than anywhere else. It is also one of those races that makes gamblers of everyone, even those who usually have no interest in racing or in betting.

Office workers arrange sweepstakes, grandparents pay their one visit per year to the betting shop and everything comes to a halt for what is, quite simply, the biggest horse racing spectacle of the year.

Fairy tales can come true

It is a well known rule that to make money from betting on the horses, you need to use your head, not your heart. This is why the bookmakers find Grand National day so profitable, with those who know next to nothing placing random wagers on horses on the basis of their name, colour or some soul-wrenching story. Just occasionally, however, the heart can get the last laugh.

In 2013, the race was won by Auroras Encore, an 11-year-old gelding that few had heard of, ridden by a 23-year-old jockey in his first Grand National. At 66/1, the horse was the biggest long shot to win the race since 1947.

After that taste of glory, Auroras Encore never won again, and he quietly retired the following year. But this year, his trainer Sue Smith has another horse up her sleeve that bears some striking similarities. Could lightning strike twice?

Sue just knows

The Grand National is still more than a month away, and we have the small matter of the Cheltenham Festival to enjoy first. Nevertheless, the moment the weights were announced, tipsters at Racing Tips were on hand with their grand national predictions and of the 100 or more initial entries, one outsider has attracted more chatter and early bets than all the rest.

I Just Know is the horse that many people think is going to do it again for Sue Smith. He currently stands at 55th in the entry list, meaning that at least 15 will have to withdraw for him to get a run – on the evidence of past years, his participation is all but assured.

What makes I Just Know more than just an outsider with an interesting back story, though, is the reaction he has provoked in the racing community. Initially at 100/1, he accounted for an incredible 24 percent of bets placed online on the first morning, and within hours, bookmakers had shortened the odds to 50/1 or lower.

Smith said: “Right from day one, he’s always been an impressive jumper. The way we’re going now with him, this is one of the fairly obvious steps.”

When the heart rules the head

The eight-year-old was last seen in action at Catterick, winning the North Yorkshire Grand National Handicap Chase on 11 January. The win was especially poignant, as it was enjoyed by owner Ray Scholey, who passed away the following week at the age of 88.

To claim glory at Aintree would be a fitting tribute to a man who had a lifelong love of horse racing and would mean the world to his widow Margaret and his son Michael. With this one, there is more at stake than simply a Cinderella story, or a possibility of lightning striking twice for a talented trainer, and to back I Just Know on such emotional grounds breaks every rule in the gambler’s book.

However, as the betting patterns so far have demonstrated, sometimes, even the most pragmatic racing fans have to throw the rule book out of the window and go with their hearts.