Zac Purton has all of the momentum, but Douglas Whyte has the right book of rides to reclaim Jockey Challenge superiority and deserves his spot on top of early betting markets. Purton, fresh off a mid-week treble at Happy Valley, has rocketed into second place in the jockeys' table over the past month and has nine rides today at Sha Tin. Whyte also has nine rides, with short-priced favourites sprinkled throughout, including the dominant Ambitious Dragon in the Group One Citibank Hong Kong Gold Cup. After reference odds had him $1.70, the Durban Demon shortened to $1.65 when betting opened, with Purton second pick on $3.60. Between them, Whyte and Purton have won the last five Challenges, and after third-pick Matthew Chadwick ($8), there is a big drop off to Keith Yeung Ming-lun and Olivier Doleuze at $20. The feature race aside, Whyte has some other top hopes, starting with the Derek Cruz-trained Enjoy The Fun, who was an early favourite in the opening event. Early markets can be unreliable, but the fact each one of Whyte's rides was single-figure odds in early betting tells the story of his Jockey Challenge chances.