Rarely does a two-time reigning Horse of the Year return with as many question marks as Ambitious Dragon, Hong Kong's highest rated thoroughbred who fell short of his three biggest targets last season and starts this term without a confirmed jockey.

Such was the six-year-old's frustrating inability to put the 2011-12 crown beyond doubt with a marquee performance, most expected champion sprinter Little Bridge to be given the gong after his fresh-in-the-mind Royal Ascot triumph.

Ambitious Dragon will resume in October's National Day Cup or later that month, with trainer Tony Millard yet to declare who will ride his star. But, win or lose, the Hong Kong Cup on international day will be a defining day for the horse.

Question marks also swirl around Ambitious Dragon's great rival and reigning Hong Kong Cup winner, California Memory, who has struggled with injury since that stirring victory.

Little Bridge and Lucky Nine get the chance to settle a score on neutral ground when they square off in the Sprinters Stakes in Japan later this month.

For now, it seems Little Bridge has stepped into the void left by Sacred Kingdom as the best sprinter in town, a title left vacant last season as horses took turns in the Speed Series, but there's still a lack of depth, at least by local standards, in the sprint ranks.

Joy And Fun hasn't let anyone down yet, but is now nine, while Entrapment has again been sidelined for an extended period. Eagle Regiment has yet to handle a turn and is also coming off an injury-enforced lay-off.

Admiration and Captain Sweet only need to make marginal improvement to be major players in the big sprints, while Best Eleven and Arrived Ahead are close in the chasing pack.

Caspar Fownes seems intent on stretching Lucky Nine to the mile races, a category which also lacks some lustre after the retirement of Able One and the decline of Beauty Flash. Glorious Days is the obvious choice as the next dominant miler. He is yet to win a Group One, but a late-season trip to Japan will have brought the horse on.

John Moore has already shelved plans to take Xtension to Melbourne, and will stay home and attempt to add to his two straight Champion Miles.

As always, Moore has a glut of talent in the top ranks, including Admiration and Captain Sweet. Moore's Dominant, Military Attack, Dan Excel, Smart Giant, Same World, Packing Whiz and Zaidan - whose runner-up performance in Singapore flagged him as a genuine Group One horse - all come out of last season's promising four-year-old crop.

The farcical running of the three age-restricted features didn't help when assessing the group, but it is from where the next big-race contenders will emerge.

Also from that age bracket, Fay Fay, Real Specialist and Sweet Orange will be serious players at a mile and beyond.

Thumbs Up produced the best local effort for more than a decade in the Hong Kong Vase, and should be joined by Dominant and last season's champion stayer, Liberator, over 2,400m in December. It looms as a strong local team, but trainers face the challenge of getting there via unsuitable lead-up races.