RUN RATING: ALL MATTER OF OPINION.

Byline: Brett Pauly Daily News Staff Writer

As many skiers have found out the hard way, rating runs is a subjective matter that is decided by the resort's management and can result in some questionable calls.

The toughest runs at Snowcrest, for example, are flagged by single black diamonds - for advanced skiers - but in all likelihood should be considered double black diamonds - experts only. Over at Snow Summit, some double blacks might actually be blue squares - for intermediates.

``It's a relative scale. It recognizes the relative difficulty of trails at the resort you're visiting at that particular time,'' said Michael Berry, president of the Denver-based National Ski Areas Association, a trade group for the resort industry.

And it's a marketing tool, as one local resort manager pointed out: ``If you advertise tougher runs, you attract higher-caliber skiers.''

Why isn't there a uniform scale?

Too many variables, according to Berry. Vertical drop divided by the run's length provides a crude formula, but throw in obstacles, regional variations and snow-surface conditions - moguls vs. flat, ice vs. groomed - and the mix becomes too great to rate.

``It probably is an impossibility,'' Berry said. ``What may be a blue trail on Monday could be a black trail on Tuesday.''

In lieu of a national measure, resorts warn patrons of the hazards by way of skier and snowboarder responsibility codes.

``What we sell is excitement,'' Berry said. ``In our sport there are elements of risk, and we don't hesitate to tell people that.''