The unthinkable happened at Randwick last Saturday – New Zealand’s supposedly potent contingent came up with virtually nothing against the best Aussie three-year-old males in the Australian Derby. The best any of them managed in the $2 million classic was fourth by our own Derby winner Vin De Dance, soundly beaten along with his peers by not one but three Australian-bred, owned and trained rivals. Let’s not get too carried away here – not every middle-distance …