THE sport of horse-racing prospers because it is based on a difference of opinion that can only be resolved over a matter of furlongs.

Robin Oakley has taken this essential ingredient and concocted a glorious argument of a book. His attempt to name the top 100 racehorses of all time would cause a row in a Trappist monastery.

"I was at the Cheltenham Literary Festival recently," he said, referring to the lesser of the festivals in that wonderful spa town, "and I was assailed by those furthering the claims of horses I had under-rated or left out of my list. Willie Wumpkins was a favourite of one of my more vociferous challengers."

Willie Wumpkins won the three-mile hurdle at Cheltenham on three occasions, displaying admirable characteristics, but Oakley's ruminations take on a contemporary relevance as Frankel, the four-year-old trained by Henry Cecil, races for the last time in the Champions Stakes at Ascot.

Frankel's unbeaten record now stretches to 13 races and he is regarded as a viable contender as Greatest Horse of All Time.

Oakley, the turf correspondent of the Spectator and the author of numerous books on racing, has placed Frankel third on his list. It is a verdict the former political editor of the BBC is not inclined to change.

"I am quite happy about where he is," he said, having placed Frankel behind Brigadier Gerard and the peerless steeplechaser Arkle. "When I wrote the book Frankel had not yet run over 10 furlongs so in a sense it was quite easy to put Brigadier Gerard, who won 17 out of 18 races, in front of him."

Frankel, he readily admits, "is one of those horses that sets the little hairs on the back of your neck prickling". He added: "Some of his victories have been electric but it would be lovely if somebody gave him a real race of it at Ascot."

Frankel, of course, has never gone beyond 10 furlongs and the traditionalists would always insist that a mile-and-a-half is the great judge of a great horse. Oakley, however, pointed out: "It is the fashion now in breeding to put an emphasis on speed and on producing mile-and-a-quarter horses. But I am still old fashioned enough to see a horse prove himself or herself over a mile-and-a-half."

He defends the decision, though, not to send the horse to the Prix de L'Arc de Triomphe. "That was run in such extreme conditions. You would have had to have been a horse that stayed a mile-and-a-half-plus to excel in that race."

Brigadier Gerard, of course, won at a mile, a mile-and-a-quarter, and a mile-and-a-half, and beat the Mill Reef in the 2000 Guineas. Frankel, instead, regularly wins his races with ease and has had no real challenge as he performs spectacularly.

"Frankel's extraordinary victory in the 2000 Guineas pushed every other great performance I had seen to the back of my mind," he said.

Oakley admits losing sleep over the final cut to a list that in the latter stages reached 125 horses. "On reflection I am a bit sorry not to have put in Dahlia, who won a couple of King Georges, and Ballymoss, who won the St Leger in 1957 and the Arc the next year," said Oakley.

He has one reflection on the placing of Frankel. "In a sense I still feel slightly guilty about putting him ahead of See the Stars who had an incredible record over about six months, winning six Group 1 races including the 2000 Guineas, the Derby and the Arc," he said of the John Oxx-trained horse he has placed fourth.

"I feel quite bad about having Lammtarra at just 11th. He had 300 days off the track before he ran and won the Derby. He had a short career, but a glorious one."

There was a poignant backstory to the Lammtarra tale. His trainer, Alex Scott, who was shot dead by a stable employee, had placed a £1000 bet at 33-1 that Lammtarra would win the 1995 Derby. When the colt won Ladbrokes paid out to Scott's widow.

"That was a nice touch as a bet is normally regarded as dying with the bettor. It also shows that behind every great horse there is a great story and it is normally an emotional one. There is a little bit of magic to be found when you look at a great racehorse," said Oakley.

This nod to sentiment explains his placing of Red Rum at 10th when a high-class performer such as Dancing Brave trots in at No.17. "I know Red Rum was only a handicapper, though a very high-class one. But the list is more than just about performance. There was a poll taken that asked the public to name famous horses. Red Rum was first and Black Beauty was second."

Oakley is confident in naming the greatest of them all, however. "It has to be Arkle," he said of the winner of three successive Cheltenham Gold Cups from 1964.

"They had to change the rules of racing to accommodate him. There were two handicaps: one if he [Arkle] ran, another if he did not. That is the ultimate accolade. He did not just contest championship events but he ran in handicaps against high-quality horse with light weights.

"Attempting to compare Arkle with top-class Flat horses is akin to the preoccupation of medieval philosophers about how many angels could be accommodated on the head of pin. But there is a certainty: Arkle was great. There was a sense of majesty in how he crushed his opponents."

It is fitting that a horse who inspired poetry and song should be the runaway winner for Oakley. Horse-racing exists on the power of an argument, it survives through the medium of betting but it prospers on something else, something almost sentimental.

Frankel will slip away from Ascot today to make tens of millions of pounds for his owners in stud fees. It is the memories, though, that the rest of us will value.

Frankel

Born February 11, 2008

Sire Galileo Grandsire Sadler's Wells

Frankel was bred by Juddmonte Farms and is trained by Sir Henry Cecil and owned by Prince Khalid Abdulla. Named after the late American trainer Bobby Frankel.

The winning streak EBF Maiden Stakes, Newmarket, August 2010; Frank Whittle Stakes, Doncaster, September 2010; Royal Lodge Stakes, Ascot, September 2010; Dewhurst Stakes, Newmarket, October 2010; Greenham Stakes, Newbury, April 2011; 2000 Guineas, Newmarket, April 2011; St James's Palace, Ascot, June 2011; Sussex Stakes, Goodwood, July 2011; Queen Elizabeth II Stakes, Ascot, October 2011; Lockinge Stakes, Newbury, May 2012; Queen Anne Stakes, Ascot, June 2012; Sussex Stakes, Goodwood, August 2012; International Stakes, York, August 2012.

Total prize money £2.2m

*Britain and Ireland's Top 100 Racehorses of All Time, written by Robin Oakley and published by Corinthian Books, is priced at £16.99.