When British private purchase Collection raced away to throttle his rivals in the HK$16 million Mercedes-Benz Hong Kong Derby on March 22, even the racing layman had to be impressed. Here was a very handsome four-year-old who had made two runs in the race, yet left his opposition gasping as he raced away in the home straight to score by 11/2 lengths from Thumbs Up, a Group One winner of the Classic Mile in late January. The second-best barometer of the quality of this year's Derby was the big margin between second and third, with Irish import Mr Medici heading the rest 41/4 lengths behind the winner. Suspicions that this crop of classic four-year-olds may be better than average were heightened two weeks later when More Bountiful thrashed the older horses in the Group Two Chairman's Trophy at the metric mile. More Bountiful, a winner of five previous races in the season, made it number six with a sparkling piece of acceleration that saw him arrive at the post 11/2 lengths ahead of Fellowship. And that's significant because Fellowship enables you to draw direct and valid comparisons with champion and reigning Horse of the Year Good Ba Ba, who defeated him by 13/4 lengths over the very same circuit at a Group One level event in January. More Bountiful had been beaten by a nose in the Classic Mile by Thumbs Up and had finished fifth in the Derby after racing too fiercely and ultimately failing to stay. But given the way he carried on and refused to settle for Douglas Whyte, it was amazing that he finished. Of course, after watching More Bountiful thrash his rivals under special weight conditions in the Chairman's Trophy, the obvious question is how much we have undervalued the Derby form. Senior handicapper Nigel Gray gave More Bountiful a whopping 21-point lift in the domestic ratings to 124. That's eight pounds ahead of Collection, who had beaten More Bountiful by 53/4 lengths in the classic. The obvious conclusion is that Gray would love another crack at Collection to upgrade his official mark, and not just by a pound or two. Collection, More Bountiful and Derby trial (Gr 2) winner Unique Jewellery all compete in Sunday's Champions Mile. Thumbs Up will represent the four-year-old generation in the Queen Elizabeth II Cup. It will be a stern test for this season's classic form.