Today's Classic Trial at Sha Tin provides a thrilling prelude to next month's $7 million Hong Kong Derby, with three top contenders clashing in the 1,600-metre event. Although there are only 10 going to post for the Classic Trial, it is not an easy race to assess largely because the Derby is a month away and trainers with their eyes firmly on that prize will not have tightened up their big hopes for this final prep race. From a strictly Derby viewpoint, the three that matter most in this field are Billion Win, Irish Derby placegetter Desert Fox and the brilliant South African champion, Resfa. In terms of the Classic alone, it would be foolhardy to leave out Schubert, who produced a quality display to win over this trip at his last start. He will not go into the Derby friendless either and this is a good ride for Australian ace Steven King. This is an international field of some stature and the Chilean champion, Prince Albert, not really at home over 1,400 metres last time, will be the centre of considerable attention as he puts his overseas reputation on the line. Made To Figure, who won a nail-biter last time, steps up to a mile which looks fine although trainer David Oughton has reservations about him beyond that distance. Lord Of Warriors, who gained a deserved victory last time, is another who will have his credentials seriously checked today. If he comes through this well, then trainer Tony Cruz may yet have something of quality with which to work. Irish import Aislo can improve on his first run but the Patrick Biancone-trained Impressionist is not necessarily giving out the right signals in the morning. The David Harrison-ridden Winning Supreme looks to have a bit to do, even though he is very honest. Resfa is the one to beat - even though Hayes is sure to have left quite a bit to tighten up after this outing. The South African champion ran brilliantly in the International Cup when he was forced to give five pounds away to some quality horses. He finished second best of the local horses and gave a great sight in finishing fifth. As far as the Derby is concerned, the International Cup run underlined his real Classic potential, but he may still have the class to get away with this. Resfa just has to be there and is a must for all bets. Desert Fox has been pleasing trainer Oughton as he just keeps improving with each run and there is no doubt that on the day itself, he will be ripe. Michael Kinane, who rode him two starts back, was aboard in his final gallop and noted the expected improvement. Again, on what he did overseas and what has been seen to date, Desert Fox could well be right in the firing line. Despite a muddling pace last time in a race that may not have suited, he ran home well for third. Billion Win is a horse of rare heart and ability. For long he was the Derby favourite and will still be the one to beat in the eyes of many. Today's distance suits him and if he is in the firing line at the finish, none will give more. But master trainer Ivan Allan will also have left a bit to be done for the big one next month so ultimately the Classic Trial might go to a horse not destined to win the Derby. Schubert has gone on with it since winning last time and he will be ideally suited by 1,600 metres. Schubert will be value and should be taken in quinella and tierce bets. And he's almost certainly worth something on an each-way basis.