After a relatively quiet time by his high standards, Brett Prebble will firmly announce 'I'm back' by taking today's Jockey Challenge at the expense of odds-on favourite and arch-rival Douglas Whyte. Prebble has a strong book of chances, packed with winning chances throughout the afternoon and would be a fair bet to beat Whyte, even if the two were at identical prices. But with the Durban Demon posted at $1.75 last night and Prebble at $3.80, backing the Australian is a 'no brainer' for value. Whyte may even get the jump on Prebble because he rides John Size's promising debutant Dr Possible in the opening event on Chow Tai Fook day. Dr Possible has had an extended period of education under the meticulous Size and finally makes it to the races, after trialling attractively behind Malayan Bright on December 19. But Prebble power will come to the fore in the second event, where Manfred Man Ka-leung's Natural Flame was a $37 favourite on overnight markets and will probably start shorter in what looks a fairly clear-cut case of 'too smart, too good'. Prebble has each-way claims in the next two races with Mutual Friendship for Michael Chang Chun-wai, freshly dropped into Class Four, and Sean Woods' Class Five regular Pacific Alliance in the all-weather over 1,800m (race four). The enigmatic Plan B is a possibility in the fifth event, Red Ruler is showing improvement in his trackwork and commands respect in the sixth, but after that Prebble's book is all winning chances - Galen Win, Sunny Power and Glenealy Elite. Whyte has a strong, full book of 10 rides and may well win another Jockey Challenge - never write off a champion. But with Prebble being at such attractive odds, there's only one way to bet.