Castles has done his best to make it work, by using years of knowledge to select the horses, which, he says, will all most likely be in the first three favourites, headed by Kawi, which is by Zabeel son Savabeel, which won the 2004 Cox Plate at Moonee Valley in Victoria.
"I think Kawi would be the one they have to beat," he says, relaxing into the race talk he might use if he was in front of the camera on the racing channel, as he has done many times among the opportunities in what shapes as the dream job, if that is what quantifies spending your day at the office indulging in what is your passion anyway.
"His last run at Te Rapa, before being relegated, was just outstanding. He is held in enormous regard by his trainer - Allan Sharrock. He's a five-year-old, only had 15 starts, but he's won six of them. He wouldn't want it to rain."
He and Sharrock go back a bit, to when Castles first put his racing knowledge to the test on TV, while working at the Wellington Racing Club and pinch-hitting for an interviewer unable to front at the time.
The trainer was Sharrock, the horse was Raging Queen, and it was running in the New Zealand Oaks at Trentham the next day. He remembers these things, but then, it has been his life since he was a boy going to the races at Woodville with the family.
He reckons he must have been about six when he first started making a bit of money out of it, picking-up discarded betting tickets and finding some of them were actually winning punts. A few years later, while at Lindisfarne College in Hastings, he'd get the chance to go to the races, with the help of a couple of obliging teachers. He remembers these too " ... but they shall remain nameless".
A big man, who played lots of rugby and cricket, he laughs at any thought his passion might have extended to wanting to be a jockey.
A lot of horses have done the rounds since then - dogs too, as it turns out, for he did race a winner of the Auckland Greyhound Racing Cup, surpassing most of his efforts in the field of horse ownership.
While having worked for Hawke's Bay Racing for only a short time over 20 years ago, early in the term of 1990s chief executive Des Friedrich, some of his best memories of racing have been at the Hastings track.
He says it has a strategic advantage in the conditions it provides for racing over the Spring season, leading into the multi-million dollar pickings in Australia, such as the Cox Plate and the Melbourne Cup.
But he says he's looking to make sure the racecourse - one of the closest to any city centre in Australasia - is entrenched as a community-based facility and attraction, and the Daffodil Day races on Saturday are a big opportunity. "It is an amazing cause to get in behind."
Saturday's first race is at 1.10pm, the Makfi stakes at 3.41pm, and admission a donation to the cause.
