A bronze medallist last year, Thorburn has a fair knowledge of most of his opponents and the tactics they may employ.
The Auckland duo of defending champion Alex Parlane and Stephen Lett, along with Thorburn, are three of the early favourites to lift this year's title, and Thorburn is fully aware of what to expect.
"It's a high-quality field," he said.
"It's likely to be a very tight race that may only see 20sec between the top three. It's a very strong Auckland team and they'll be pushing it up front.
The field may only split up towards the end and it may come down to a race for the line."
Thorburn is picking that Otago team-mate Callan Moody could have slipped under the radar.
"Moody could have a blinder. He's due and definitely not one to write off."
Recent history suggests the winner of the North Island title progresses on to win the national title. Parlane did the double last year and Andrew Davidson (Canterbury), another in the field today, managed the feat in 2009.
That suggests the man to watch could be Lett, who won the North Island race three weeks ago.
Davidson is a former Otago champion, and along with Thorburn has a sound knowledge of what to expect on the 12km Halswell quarry course.
The course is very similar to the Otago one at Waikouaiti, although the hills are not as sharp, but it contains more undulation.
A factor motivating Thorburn is that the last Otago representative to win the national cross-country title was John Campbell in 1988, and the list of winners in the Otago vest since World War 2 is an impressive one: Chip Dunckley (1979), Dick Tayler (1973), Pat Sidon (1961), Kerry Williams (1955-57), and Harold Nelson (1946 and 1951).
Otago last won the team title in 1958, with Cliff Donaldson, Tom Marshall, Ian Martin, Ron Cain, Allan Potts, Graham Smith and Alister Murray successful on the Invercargill course.
Thorburn led Otago to bronze last year and aims to talk to the team this year of the possibilities of performing even better.
"Auckland will be the dominant force, but we've got a good team. We're definitely in the mix for another team medal."
The Otago under-16 boys team is another favoured to medal, with Otago champion Sam Bremner among the early favourites.
Unfortunately, no athlete from Otago will contest the senior women's title, but the under-19 team is favoured for a medal, Shauna Pali is a strong contender in the individual race, and Sian English should do well in the under-16 event.
In masters grades, Ray Knox, Louisa Andrew and Maria Sleeman are all in the mix to do well.
