You might win one year but you would have to be a leprechaun living off a diet of four-leaf clover smoothies to win two years in a row.

This year, Bridport's Malcolm Taylor and his dog Mocara Eddie will be gunning to be the first in the trial's 18-year history to defend the title after taking out the 2014 open event.

Exeter Sheepdog Club treasurer Wensley Middleton said organisers were expecting about 100 entries over four classes - encourage, novice, improver and open.

For the record, that's 100 dogs that are so well trained your own pooch would probably be embarrassed to be seen with them.

Mrs Middleton said each dog would have to corral three sheep around a course and into a pen.

"They've got to take them around the peg, then they go through the gap and into the race, then over a bridge and then they get them in the pen - and they have 15 minutes to do that," she said.

"Each dog starts off with 100 points and, as things go wrong, which they always do, they lose points and then in the final it's the top six dogs."

The trials will begin from 7am on both mornings to allow intrastate competitors to travel home after the event finishes on Sunday evening.

"They come from down on the Tasman Peninsula, New Norfolk, Hamilton, we've even got one who came through from King Island."

FAST FACTS

WHAT: Northern Championships Sheepdog Trials.

WHEN: Saturday, December 5 to Sunday, December 6.

WHERE: Exeter Showgrounds.