THE ETIHAD Stadium roof will be specially positioned this weekend as part of a trial to reduce glare on the playing surface while still allowing the match to take place in open air.

The western roof panel will be moved into a different position so the field will stay in shade during play as the sun moves.

This will happen at Saturday's Richmond-North Melbourne NAB Challenge match and Sunday's Carlton-Geelong clash, as part of a range of initiatives trialled ahead of the premiership season.

A fan survey last year saw 60 per cent of supporters wanted the roof open when the weather was fine.

But the glare on the surface has been a contentious issue for players with some struggling to pick up the ball when sun and shade alternates.

Broadcasters have also said the quality of their product is affected when play deviates between the light and shade.

The League's roof policy will remain the same this year, which means it will be open for afternoon games if the weather forecast permits.

When there is more than 30 per cent of a chance of rain, it will be closed before the venue is open to the public.

It will also be closed for night games.

Opening and closing the roof while patrons are inside is against the stadium's safety policy, and that is not expected to change this year.