Oddsmakers are forecasting an end to Ben So Tik-hung's domination of the Happy Valley Jockey Challenge and leading rider Brett Prebble looks the man to beat. Arch-rivals Douglas Whyte and Prebble were posted the equal favourites last night at 4.50, ahead of Jeff Lloyd at 5.50, but it gets wider after that and reflects the openness of the night's competition. Prebble is missing from the opening two events, so punters might get the best odds by holding off betting early, but his six subsequent mounts all look chances to score at least minor points. His standout looks to be Happy Tumbler in the feature race, the fifth event, but the other five all have worthwhile chances and Prebble will be finishing strongly in the back half of the card. For those seeking longer odds when the door looks open for surprises, Alex Lai Hoi-wing appeals at 18.0 in opening market. Lai opens the night with one of the strongest chances in the Class Five, consistent Joyful Years, who should be forgiven his last run on the all-weather on a wet day when a number of noted dirt performers failed to fire in the conditions. His prospects in the Challenge may hinge on a win by Joyful Years, but he also has some claims on Royal Portrait (race three), Good Luck Win (race five), Euro Swiftly (race seven) and Forever Elation (race eight).