Hold your horses - it's that time of year again. Yes, the Grand National, arguably the jewel in horse racing's crown, is almost upon us and excitement levels are beginning to ratchet up a notch or two.

When backing a horse (or getting against one by selling on its spread betting Race Index) there can be a method to the madness.

So we've had a look at some of the leading contenders for the big 4.15pm Saturday race at Aintree to run the rule over their chances.

What is the profile of a winner?

With 30 fences to navigate over 4 and a half miles, the Grand National is all about experience, willpower and, of course, stamina. Most winning horses are aged between 8 and 13 years old, and have plenty of experience of winning at distances over 3 miles.

Form is the other important factor to consider, especially in the Irish, Welsh and Scottish Nationals. Since 2000, ten champions had a run in at least one of these races and six had at least finished in the top three. Be sure to have a look at a horse's spring form too - as four of the last five winners had all previously won races in April.

Who are the main contenders this year?

This year's favourite, Teaforthee, finished the race third last year and has all the attributes of a Grand National champion. However, there aren't very many horses that perform well at Aintree after the first attempt; Hedgehunter being one of the exceptions after nearly winning the National for the second time in two years in 2006.

The other favourites this year are Tidal Bay and Long Run; however the former will have to break all manner of stats as he is a 13 year old weighing in at 11st 10lbs. In the last 60 years, only the legendary Red Rum has managed to win the race carrying that much weight and the last horse to win aged 13, Sergeant Murphy, dates back to 1923.

Long Run is certainly a class act; a former King George and Gold Cup winner. However the downside is his poor form, with only a solitary win at Kelso to his name at late. Judging by the form book it might be worth having a gander at a few of the higher priced horses.

One demanding some attention is Lion Na Bearnai, winner of the Irish National a couple of years ago and a horse who is yet to fall over fences. At 12 years old, he is one of the older horses in the race, but with Gold Cup winning jockey Davy Russell at the whip some punters believe he could be in contention.

Another of the outsiders generating some interest is Burton Port, trained by one of the best in the business in Jonjo O'Neill. Brought in as a back up to the injured Sunnyhillboy, runner up two years ago, Burton Port has been showing good form of late and is being ridden by Brian Harding, who has a terrific record in the National.

Spread betting on the Grand National

However, if all the choice is giving you a headache, why not choose to spread your bets? The glory of horse race spread betting is that by taking a flutter on some of the specials offered over the race you can apply some method to reduce the ‘lottery’ aspect of the race.

By placing either a buy or sell bet on a spread based on selections such as Number of Finishers, Winning Distance, 2nd to 3rd Distance, 1st to Last Distance, SP of winner or 1st Fence Casualties x 10, you’ll have more of an interest in the race other than just who goes past the post first.