Noodler and Slider...ouch, my feelings are hurt
But I'd have to agree with with both of your comments, there is a bit of a lack of extension at the top of the arc that would indicate a need for better timing of pressure control movements (I think I've fixed that up since this was shot) but I don't think that I would say that I've skipped the top half of the turn. To the contrary actually.
Some context here. This video was from a demo team tryout tape where I was trying a couple of new things. The terrain is very steep black (Men's Downhill at Lake Louise). The first thing I was trying was to ski with a flatter trajectory of the C.O.M to affect impulse, the second was a round top half of the arc for a stronger platform. I would agree that there is a definite rising of the C.O.M. in this video (there has to be) but I wouldn't call it up and down, I'd ask you to look at where the legs are most extended and where they are most bent. I would call it up and down if my legs where most extended in between turns but that's actually where they are most bent, if you look closely that's also when the C.O.M. is directly over the B.O.S. so in terms of verticallity, yes the C.O.M. is at it's highest point in relationship to the ground but closest in terms of it's relationship to the B.O.S. This is a short radius turn not a slalom turn so I think the roundness of the turn shape actually creates a look of moving more vertical.
Here's another video, I'm the second skier, once again asked to demonstrate as round a short turn as I possibly can; http://s104.photobucket.com/albums/m...hortrblack.flv
You'll see the skis come off the snow in between a couple of the turns in this one also but once again the turning of the legs creates the extension and the separtation of the B.O.S. and the C.O.M. in a vertical sense but on an inclined axis (deflection). This video is at Sunshine Village on Bye Bye Bowl, very steep black and one of my favourites runs anywhere! I suppose you could call it the same thing, a lack of pressure control but in this instance to get as much deflection as possible I went with more of a retraction move instead of flexion. I think expert skiing demands a bit of both, depending on the snow, terrain, speed, turn shape, etc.
In terms of my thought process when skiing a short turn I think of two things and I actually say it in my head for a bit of a timing tool, "Balance - Pressure". Balance at the top of the arc through a stong steering effort and establishing a good platform to move from, pressure control at the bottom through continued steering and guiding the base back under the mass. To make this happen I view a short radius turn in two halves, and it's exactly that, halves, so the top half should take just as long as the bottom half. I see a lot of skiers that seem to be in a hurry to get to the end of the turn. I like to focus on steering in the early part of the turn as much as I do through the end. I also like to have the impulse in the fall line. These videos the impulse is a bit later then what I'm doing now but it's still fairly early, you can see the snow come off the skis more in the middle of the turn and to the side of the run vs. at the end and completely down the slope.
Last thing that I would add, so you can maybe see my point of view, is that I like to ski with the idea that the Base of Support is manipulated through the arc to either deflect, support or capture the Centre of Mass in four planes. Vertical, fore and aft, rotational and lateral. Simply put, the B.O.S. does most of the work the C.O.M. is along for the ride. The images below I think highlight this and I think that the videos do as well. In general terms (not completely precise) the upper body stays quiet while the lower body is active and active in all four planes. Balance is an action-not a position.
Thanks very much Bud for the compliment but also for creating what I think might be a very interesting discussion.