By Helen Briggs
BBC News science reporter
Science is cracking some of the secrets of equine success.
Eclipse is described by some as the greatest racehorse of all time
The 18th Century horse Eclipse was a legendary figure in horse racing, contributing to the bloodlines of 80% of modern thoroughbreds.
Yet, despite his unbeaten record, Eclipse, the "father of modern racehorses" was perfectly average in the leg department.
That is the verdict of scientists at the Royal Veterinary College (RVC), who have reconstructed one of the horse's legs to look at what made him a winner.
It appears that Eclipse's body shape and movement were in the middle of the normal range, giving him the perfect conformation for running.
"To be average is good from the point of view of a racehorse," Dr Alan Wilson of the RVC told the BBC News website.
"From the point of view of his bones, he's right in the middle of what would prove typical for a racehorse."
Eclipse was born in 1764, the year of a solar eclipse. He easily outclassed other racehorses, winning 18 races before being retired to stud, chiefly because nobody wanted to pit their horses against him.
He sired three Derby winners and found his way into the bloodlines of a great many modern thoroughbreds.
The horse was dissected after his death and his skeleton has been on show for many years at the National Horseracing Museum in Newmarket.
Dr Wilson and graduate student Renate Weller used the skeleton to try to work out the secret of his success.
Using portraits of Eclipse and contemporary accounts of the horse running, they reconstructed one of his legs and compared it with the shape and structure of modern horses.
They then analysed his skeleton and developed computer models of horse movement.
They found that Eclipse was perfectly average when it came to the shape and morphology of his leg bones.
It appears that hundreds of years of modern breeding have hardly changed the "recipe" for a winning racehorse.
Dr Wilson said it was fascinating to use old skeletons as a reservoir of information to see how perceptions have changed over the years for how people think a racehorse should look.
"If you look at a Stubbs painting, it doesn't look much like a modern racehorse," he said. "But it's our perception that's changed and not the horses."
Old paintings might not provide an accurate record, he said, because they were painted to impress the owner and probably exaggerated certain features of the horse.
So, if Eclipse's bone structure was not exceptional, what made him the winner he was?
His large heart and powerful lungs - seen at dissection - would have played a role. Another attribute that gave certain horses an edge over the opposition was their "spirit" or "will to win", said Dr Wilson.
Further answers may lie with planned DNA studies of Eclipse. Scientists hope to extract DNA from the animal's bones, hooves and teeth to look at his genetic recipe.
Until then, racing enthusiasts may have to rely on the old skills of weighing up a horse's form and fitness.
But this latest study does show, perhaps, that there is an element of truth to the old adage that some punters can pick a winner simply by looking at a horse.