Originally Posted by boboco
I want to get a true perception of my development when I hit the slopes this season.
What you can survive has no relation to how developed your skiing is. Good skiing is about mastering skill sets such as edging, steering, shaping turns, body-mass movements, pressure control, etc--and then applying blends of those skills to master the conditions you are faced with in a graceful and efficient way.
While you should certainly seek out conditions that will challenge you, be aware that it is difficult to develop skills in environments where you are not completely comfortable. For that reason, if you are constantly chasing slope ratings, you may find yourself never getting better. You may be able to survive a black or a double black, but you won't look good doing it and you won't truly be skiing it. Go to slopes that will challenge you to test what you have learned, but do your learning on more comfortable slopes.
There is no standard for rating ski runs; they are relative to other runs at that ski resort. As a result, there can be vast differences between the perceived difficulty of the same ratings between ski resorts. The following generalizations are how I think about these designations.
Green: Beginner runs that almost anyone should be able to get down. In some cases they may be intimidating for first timers though. For example, Sundance at Arapahoe Basin has a section that is almost as steep as High Noon (a blue run) and it has a double fall line. The top half of Quicksilver at Crystal Mt (Washington) is steep enough to be scary. Green runs are almost always groomed (I don't think I've ever encountered a green run that is not).
Blue: Most skiers should be able to ski these runs. In general, they will be of moderate pitch, but occassionally, you will find blues that are fairly steep. For example, Franz's at Whistler, Starfire at Keystone, and Gros Ventre at Jackson Hole both have some steep sections that may be intimidating for some. Blue runs are often groomed. When they are not, they will usually not have a steep pitch. In some cases, the difference between a blue and a black run will simply be that the former is groomed.
Double Blue: A few resorts offer this designation. Usually what this means is that these runs are not guaranteed to be groomed. They may also have longer steep sections than their blue counterparts.
Black: Usually fairly steep and usually not groomed. Black runs will typically have bumps on them. Some black runs can be very steep (such as Shale Slope at Whistler which is over 40 degrees), but they will have plenty of room to traverse and falls will generally not result in hitting rocks or trees. Also, while the steepest section of a black run may be similar to the steepest section of an blue run, the black designation may reflect the fact that the pitch is more sustained and/or very narrow. Black runs may also be designated in gladed areas. Black runs can be groomed, and the steeper blacks are sometimes groomed by winch-cat.
Double Black: This is an "experts only" designation, but you will find a great deal of variation across resorts. The most difficult of double-blacks will incorporate steep slopes (over 40 degrees) with the potential that falls will result in injury due to rocks and trees. They are often narrow (at least in terms of available lines), and they may require mandatory air or a straightline. If a run is designated double black, but can be groomed, it will not stack up to the more representative double blacks in the country. Also, the difficulty of these runs can be dramatically affected by conditions (to the point where they cannot be safely skied). Finally, even within the resort, there can be tremendous variation among double-blacks. Don't assume because you skied the run next door, you can handle the one you are thinking about. For example, there is a big difference between Corbett's and Alta One at Jackson Hole.