Chapman, 74, will be handing in his training licence at the end of this month and his granddaughter Ruth Carr will be taking over the day-to-day running of Mowbray House at Stillington, near Easingwold, but that will not bring an end to a splendid career making the most of what he modestly calls "quirky" horses.

His speciality has been in buying animals which had been rejected by other trainers and the perfect example of his art is Quito, bought for 3,500 guineas at Newmarket and the winner of £480,000 in prize-money. The recently-retired Sharp Hat ran 218 races, won 25 of them, was second 25 times and third on 26 occasions.

Redoubtable was another stable star, so were Glencroft (17 wins), Chaplin's Club (24), Higham Grey (18), Karen's Star (12), Scotch Imp (10) and Tempering, who won 22 races at Southwell but never impressed anywhere else. Then there was Soba, the nearest thing to a Classic horse Chapman handled.

They all gallop across Chapman's memory as he remembers the days, the deals, the characters and the occasional bet.

He and his wife Marion, a key member of the Chapman team, recall the time they set off for a week's holiday in Scotland and were back at home a day later. The following year they managed two days holiday.

It all began in 1952 when Chapman, then 18, and his brother John, the younger by two years who was to become a partner in many of the horses David owned and trained, moved to Mowbray House from the family farm at Austhorpe, parts of which date back to the 13th century.

"The locals did not expect us to last any more than five years," recalls Chapman. He is still there.

"My father and grandfather had had race-horses but I had to wait 10 years before I had my first – it was called Findon Hill and arrived here from Ryan Price's yard on Christmas Eve 1962. He was bit of a rogue. We'd be hunting and he would tear towards a thorn hedge then put the brakes on; I'd end up in the hedge," says Chapman.

His first winner came with Black Furrow at Easingwold point-to-point in 1964. Among the beaten horses was Manifest, who would start as favourite for the Grand National the following year.

Second places in selling races brought in extra cash and helped persuade Chapman to take out a licence to train under National Hunt rules and confidence grew when a horse bred by his father called Last of the Moors, the last foal by the stallion John Moore, a Chester Cup winner, ran at Hexham against a well-fancied animal trained by Arthur Stephenson.

"He had never beaten another horse but I said to my father 'I think we can win this'," recalls Chapman. "'Don't talk silly,' father said, so I didn't have a lot on him; he won at 25-1."

He took out a licence to train on the Flat in 1967 and began by buying sprinters in the weeks before Christmas when owners were looking to off-load their horses rather than pay to keep them in the days before all-weather racing.

Karen's Star was one bargain, going on win several races, then there was Music Night who won a valuable race at Pontefract under John Lowe then finished fourth with Lester Piggott in the saddle at York, despite the race being run on soft ground, which the previous trainer had said the horse would not enjoy.

"I asked Piggott what he thought and he said we would win on the soft," recalls Chapman. "So we ran him in a good race at Redcar on softish ground and the following day's headline in the racing press was 'Music Night lands massive gamble'. I had had a little bet - nothing 'massive' – but the owners were not impressed and took him out of my yard. He never won anything afterwards but someone had certainly had a good bet on him at Redcar."

Then came the stroke of fortune which established Chapman as a trainer to watch. He had bought a "nice little filly" called Mild Wind from Lord Howard de Walden and sold it to his sister Muriel, who sent her to Peter Easterby's Most Secret who commanded a £180 stud fee. The result was the flying filly Soba, but the early indications were not promising.

"She was no good as a two-year-old, racing just didn't seem to click with her," recalls the trainer. "She had potential as she proved when David Nicholls rode her in a gallop with a good three-year-old called Relative Ease but the best she could manage in her first year racing was third.

"First time out as a three-year-old she ran against an odds-on favourite at Thirsk and I told Nicholls to bury her in the middle of the field. She shot out of the stalls, made all and won comfortably. Nicholls apologised: 'I'm sorry guv'nor, I couldn't hold her'."

Another smile came and went.

Soba won 11 of her 14 starts as a three-year old in 1982 and the following year was unfortunate to come up against the brilliant Habibti, who four times managed to get his head in front.

"At the end of her four-year-old season Muriel had done a deal with Robert Sangster to send her to Golden Fleece," says Chapman.

"As it happened, Habibti didn't train on so it might have been the wrong thing to do. Still, we don't know that Soba would have, do we?"

Chapman paid 6,000 guineas for Glencroft, who won nine races as a four-year-old including one carrying 10st 10lbs at York which Timeform described as "the sprinting performance of the decade". Another prolific winner at the time was Chaplin's Club, owned by Scarborough-born millionaire Peter Savill and when they met Glencroft finished in front, preventing Savill's horse winning his 10th race of the summer.

"Glencroft was a class horse," says Chapman. "He was two stone better than Chaplin's Club. I don't really know which was the better, Soba or Glencroft. Soba was just below Classic standard, which is generally in the 120 range; Glencroft's best rating was 112."

He says of his knack with horses "lots of farmers make good trainer, we are all stock dealers at heart" and will continue to visit the sales looking for more bargains as his granddaughter make progress with the 28 or so animals at Mowbray House, several of them in full training to take advantage of the re-opening of the all-weather at Southwell.

He looks forward to more winners before he steps aside, conscious that in racing, of all sports, nothing is guaranteed. He and Marion cherish their memories of great wins and great days – like the never-to-be forgotten afternoon when Prince Charles and Lady Diana Spencer married.

"We had a winner that day called Wedded Bliss," remembered Marion. "And the same afternoon there was another winner called Champagne Charlie," added her husband. "Lots of housewives backed them in a double." Smiles all round.