Addictive Habit's sire is Columbia, standing in Masterton, who fetched $1.4 million at the Karaka yearling sales.
Columbia is the progeny of stud owner Sir Patrick Hogan's stallion, Zabeel, out of dam Eight Carat who won a treble of Broodmare of the Year titles from 1995-97.
"It's one of the best bloodlines you can get," Roddick says, adding Columbia went to stud. He sired Stirling Prince, a gelding under the tutelage of Wayne and Vanessa Hillis in Auckland.
Addictive Habit's mother was the Roddick-owned Chasing The Habit who died last year after a foaling mishap.
"She was the half sister to the champion horse, Rough Habit, who won 11 group one races and we also bred him," she says of Rough Habit, who has 29 wins to his name and is retired at Cambridge Lodge.
For the record, Chasing The Habit has left behind eight winners.
"He was a one-in-a-lifetime horse, that's for sure."
Addictive Habit, who will have Hayden Tinsley in the saddle, has had three starts with a victory and two second placings.
"It was beaten by a nose in one race and by half a head in the other," Roddick says, pleased with how much ability Addictive Habit has shown to date.
Tinsley rode him to runner-up at the Riders Stake in Otaki on July 28 while South African jockey Jason Jago, who rides Somervell's Fleur de Lune in the premier NZ Bloodstock Insurance Spring Classic at 5.07pm, rode Addictive Habit to victory in his maiden race at Tauranga on July 18. The other second came at Pukekohe on September 21.
The other litmus test for him after today's Guineas will be the Auckland Derby in March next year.
As cliched as it may sound, the Roddicks' labour of love is a co-operative effort.
"We do all the work together and decide each year which mares to send to stallions for foals."
Perish any thoughts of getting comfortable as horse breeders.
"It's a very hard business because you never know which foal will be good. It's a bit like a pot-luck dinner," Roddick says with a laugh.
So how many horses have the couple bred in four decades?
"I'd hate to say," she says but accepts it's not always easy to know when they should sell a horse or ruing the benefit of hindsight to have kept it.
Roddick, who has some good friends in Invercargill, has a 6-year-old mare, Petty Lane, who registered five victories and as many second placings.
A 3-year-old filly, Queen's Habit, will be running her maiden race at Ascot Park in a fortnight under the watchful eye of trainer Lisa Vaughan.
The horses have syndicated ownership.
Citi Habit, who has sired Defend Citi, has won six races, as well as finishing runner-up in the Brisbane Cup in 2002.
So is there a Bad Habit by any chance?
"A lot of people have asked me that and I haven't yet because I haven't found the right one but it I reckon it isn't too far away," a jovial Roddick says, adding most of the progeny have a wonderful temperament.