FREMANTLE onballer Paul Duffield has pointed to his side’s unwavering belief in Mark Harvey’s game plan as a key ingredient to his side’s impressive opening month to the AFL season.

Despite a 15-point loss to St Kilda at Etihad Stadium on Sunday, Duffield said the results of the first four weeks prove Freo are heading in the right direction.

“St Kilda are a side that we haven’t gone too good against in recent years, and while we’re disappointed in terms of the final result, I think the guys showed a lot of resolve,” he said.

“We’re three (wins) and one (loss) now, so looking at the draw we’re pretty happy with that. Obviously we’d love to be four and zero, but the main thing is we’ve been competitive.”

Fremantle has been resolute in the face of opposition pressure so far in 2010, and have continued to hold their structure across the ground in all four games. Despite falling behind by as much as 25 points late in the final term on Sunday, Freo consistently stuck to their game plan and were rewarded with late goals to reduce the final margin.

“I think (our improvement) comes with a little bit more experience, but a lot of that is also good coaching as well as good leadership out on the ground in maintaining those structures,” Duffield said.

“We know now that if those structures don’t fall down, we can stay in games a lot longer. We’ve just got to stick to what we’re doing, and hopefully the results will fall our way.”

Duffield has been one of many Fremantle players to take a step up this season, and continued his impressive start to the year on Sunday, collecting 36 possessions.

While the side is now considered a genuine chance of a top four finish by many pundits, Duffield said Fremantle's playing group wasn't getting too far ahead of themselves.

“St Kilda competed for a premiership last year, and we probably have a little way to go to get to that level,” he said.

“We’re staying realistic; we know we’ve got a lot of improvement still. We just have to keep doing what we’re doing well.”