Psst, we are going to let you into a secret.

We already know the winner of the Grand National here at Argus House, or, to be more precise, Patrick Kelly does.

Followers of four-legged sports know Kelly as our greyhound tipster but he is also, for want of a better description, a Grand National anorak.

Kelly loves the Aintree showpiece and painstaking research has produced an enviable record for picking the winner of the big race, or at least getting a good run for your money.

"It has been my baby for a long time," said Kelly. "I have always been a massive Grand National fan.

"I found the winner last year, Numbersixvalverde. I went in 1999, the year Bobbyjo won. I had a saver on that as well. It has been a very lucky race for me."

There is more to it than luck. Kelly analyses, in enormous depth, a number of key factors which point to the horse best equipped to triumph over the daunting fences and gruelling four-and-a-half mile trip.

Did you know, for example, that only four clear favourites and one joint-favourite have won since the famous victory by 100-1 shot Foinavon 40 years ago?

The odds are against the actual market leader prevailing but, according to Kelly, "the vast majority of winners since 1967 have come from a range of quotes between 7-1 and 16-1."

He goes to extraordinary lengths to narrow the field down. Take this little nugget. "Of the 160 horses placed in the last 40 runnings, an incredible tally of 123 have carried 11 stone or less."

Now we are getting somewhere. Forget the favourite, anything humping a heavy weight and horses winning last time out. Kelly points out: "Only Hedgehunter (2005), Bobbyjo (1999) and Seagram (1991) have enjoyed this distinction in 18 runnings since 1988."

Age, fitness, stamina, the going, preparation races, previous Aintree experience and breeding are all taken into account as well by our Grand National guru in arriving at his verdict.

So who are Kelly's heroes? He believes Numbersixvalverde, carrying nine pounds more than last year, has a "real chance" of becoming the first since the great Red Rum in 1974 to complete back-to-back wins and expects the Irish-trained 11-year-old to finish in the places.

If you are looking for an outsider, Kelly recommends another Irish-trainer runner, Silver Birch, a previous winner of the Welsh Grand National and Beecher Chase over three miles and three furlongs at Aintree.

The finishing post is coming into view. Chasing the winner home, Kelly reckons with the ground firmer than normal, will be McKelvey, who "loves to hear his hooves rattle".

Now for the name you have all been waiting for but I will tease you a little longer with a few clues.

The 2007 Grand National winner has, Kelly eulogises, "been placed in 13 of his 19 career starts, has never fallen over fences, acts on any going, is very much a spring horse, shows his best form on a flat track and is easily the best handicapped horse in the race."

Just for good measure, the National normally throws up a romantic tale and Kelly's tip is owned by octogenerian Mercy Rimell, whose late husband Fred trained the winner no fewer than four times.

I'll keep you in suspense no longer. The name of the horse is Simon. It really is that simple!