Pedigree authority Matthew Ennis says Atullibigeal and Straight Arron profile as the BMW Hong Kong Derby runners who represent the biggest threats to favourite Beauty Eternal at Sha Tin on Sunday.

Ennis, managing director of breeding research tool G1 Goldmine, analysed not only the pedigrees of this year’s 14 Derby contenders but also the breeding of the past 20 Derby champions in an effort to identify betting value in Hong Kong’s most prestigious race.

The tool, which thoroughbred breeders employ to find perfect stallions for their prized mares based on proven crosses and yearling buyers use to evaluate sales catalogues, allocates a rating – Outstanding, Excellent, Good, Neutral or Poor – to each galloper based on how similar they are to international stakes winners and the results of their respective crosses.

Beauty Eternal, who could start this weekend’s Derby as one of the race’s hottest-ever favourites as the hype surrounding John Size’s youngster continues to grow, boasts one of the three Outstanding pedigrees, but Ennis believes 1,600m is his optimal trip.

“There’s been success over a bit more of a distance, like 2,000m, but most of Beauty Eternal’s aptitude profile is definitely weighted below a mile. He looks like a perfect miler with a big question mark for anything over 2,000m,” Ennis said, although the G1 Goldmine boss acknowledges the favourite could be one out of the box and notes the stakes winner with the most similar pedigree to that of Zac Purton’s mount is 2018 Group One VRC Oaks (2,500m) heroine Aristia.

Super Sunny Sing is another of the Derby competitors whose pedigree rates as Outstanding, but that appraisal is independent of trip. Factor in the 2,000m journey and, according to Ennis, the Classic Cup victor should be one of the Derby outsiders.

“Forgetting about form, I’ve no idea how Super Sunny Sing is the Derby second favourite with fixed-odds bookmakers here in Australia,” Ennis said from G1 Goldmine’s base in Sydney’s southern suburbs.

“Looking at his pedigree, you’d say he’s got zero chance. If he was lining up in a race over 1,200m or 1,400m, you’d be rubbing your hands together, but we’re talking about a Derby over 2,000m.”

Of the many stakes winners to whom Super Sunny Sing is closely related, his pedigree is most similar to those of two Western Australia-based sprinters, 2021 Group One Winterbottom Stakes (1,200m) winner Graceful Girl and the beaten favourite for the 2017 edition of that elite event, State Solicitor.

With Ennis putting his pen through Super Sunny Sing – whose victories beyond sprint distances are proving pleasant surprises to the Hong Kong-based bloodstock agent who sourced him, David Price – he is looking to the engine’s third Outstanding rater, Atullibigeal, and one from the next tier down whose pedigree screams top-level 2,000m performer, Straight Arron, to take the fight to Beauty Eternal.

“One of the reasons Atullibigeal gets promoted on the system is both of his tail female families are influencing his pedigree,” Ennis said.

“We see it, but we don’t see as often as we’d like. We see it a lot in elite horses where that tail female from the sire and that tail female from the dam are positive contributors to the pedigree. It’s really potent when those tail females then complement each other.

“From a pedigree perspective, he’s the most interesting Derby runner. There are so many crosses within five generations of his pedigree with proven success over the race distance.”

Among Atullibigeal’s closest relatives is, arguably, Australia’s premier active galloper, Anamoe, who won last year’s Group One Cox Plate (2,040m) 12 months after many pundits thought he should have been promoted from second to first on protest.

Straight Arron’s pedigree scores an Excellent rating, but Ennis thinks he is bred to do his best work in a classic contest like the Derby.

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“The 2,000m distance is going to be perfect for Straight Arron. He’s closely related to not only multiple stakes winners but also multiple stakes winners who’ve excelled over the trip, including Russian Emperor’s dam, Atlantic Jewel,” Ennis said.

“His two tail female families are in sync and performing better than expected. If you look at the tail female of the dam, Gay Poss, she’s working with every single spot of Fastnet Rock’s family. That’s a beautiful thing to see. He could cause an upset.”