The buzz as the bidding ticks into the millions can be "compelling" theater as royalty and billionaires compete to buy the best new race horses on the market.

The annual battle of the deepest pockets occurs at Tattersalls' premier yearling sale - known as Book 1 -- where the most enticing one-year-old prospects go under the hammer.

Last year, 106.5 million guineas changed hands - the equivalent to $138 million - and this year's October renewal promises to break the bank once again.

Of the 552 lots in total, 160 have been sired by the five greatest British and Irish stallions of their generation: Galileo, Dubawi, Frankel, Kingman and Sea the Stars.

At the 2018 sale, a one-year-old son of Dubawi was the subject of a fierce bidding war, eventually selling for £3.675m ($4.8m) to David Redvers for Qatar Racing.

"It is great theater," said Jimmy George, the marketing manager of Tattersalls, a firm founded in 1766 in London but now based in UK horse racing hotbed Newmarket.

"There are times when it is so extraordinarily compelling in the ring and you can't help but watch it all unfold. That's the beauty of Tattersalls and this sale. It's a little bit special."

'Outstanding stallions'

This year, 29 yearlings are from Dubawi, who stands at the Darley stud in Newmarket for Dubai ruler Sheikh Mohammed. The prodigious stallion sired last year's champion two-year-old Too Darn Hot and boasts a stud fee in excess of $300,000.

There will also be serious interest in the progeny of legendary race horse Frankel, who won all 14 races he entered before going to stud, where he commands about $218,000 a time. Given he sired the winners of the English Oaks (Anapurna) and the St. Leger (Logician) this year -- another son Cracksman was the world's top-rated race horse in 2018 -- his lots are likely to attract plenty of money.

Then there is offspring from Frankel's father Galileo, who is one of the world's most expensive stallions with an undisclosed stud fee reported to be about at the Coolmore Stud in Ireland.

"Book 1 of the yearling sale is the most prestigious yearling sale in Europe if not the whole world these days," adds George. "It's very prestigious and I'd say the quality of stallions Britain and Ireland right now is as good as it's been in living memory. We've got a team of truly outstanding stallions."

'A who's who? of buyers'

Tattersalls sells about 10,000 horses each year but the buzz around it's most prestigious yearling sale is unlike any other, according to those at the company.

Auctioneers take half-hour stints with the gavel in bidding that can be breathtaking in terms of the speed and the numbers in question.

"It's a very important time; the truth is it can make you or break you over the next two years," champion trainer John Gosden told the Racing Post.

"If you get the wrong yearlings or buy the ones who don't work out, it can be instrumental on the whole success of your stable."

Trying to pick out which horse might break the record books is virtually impossible, according to George, who says any of the yearlings from the top stallions could sell for seriously large sums of money in the event of wealthy owners locking financial horns.

Buyers are expected from roughly 50 countries with wealthy suitors from the likes of Japan, the United States, Ireland, France, Dubai, Qatar and Hong Kong.

Among the notable names to have attended the sale over the years are Britain's King George V, who was a visitor in 1923, while Sheikh Mohammed, Sheikh Fahad and Sheikh Hamdan make regular appearances.

"It's like a who's who of buyers as it's a passion for them," says George. "This is the sale that the top buyers need to be at in order to compete at the highest level to access the best horses available. Many of them have been coming for years and their enthusiasm and commitment is as strong as ever. It only adds to the pure theater of it all."

Unearthing the next Derby winner

Tattersalls takes a 5 per cent stake from each horse sold, but its reputation as a premier auction house is enhanced if the horses sold become big stars in their racing careers.

Buyers will do their "due diligence," studying pedigree, provenance and the condition of the horse itself before entering the bidding, according to Gosden.

However, with one-year-olds, there is no guarantee of glory in the big races, making the risk of the riches shelled out all the more remarkable

"The best stallions have the highest percentage of superior racehorses but not all are going to be fantastic because nature works in weird and wonderful ways," said George.

"As humans, we're effectively accidents but there's more thought here as you send your mare to the best possible stallion you can afford, and then you let nature take its course.

"There's no guarantee of success in this. All buyers are trying to do is use their expertise to narrow down odds to the best of their ability. Not everyone falls in love with the same type of horses. By and large only thing that separates people trying to buy a champion racehorse is how much financial resource they have for that. All have the same aim...to have a champion. This is about the next winner of the Derby or Oaks, and beyond."

Overall, the average price of each of the 500-plus horses sold is expected to be about $330,000.

George has lost count of the number of sales he has attended but this annual three-day event always adds a further frisson of excitement.

"There's genuine drama and excitement as the horses come into the ring," he said. "There's big expectation, it will be standing room alone and what's great is anyone can attend. It's a public auction open to everyone. And the buyers know they won't be short of quality."