I hope this makes senseWell I am glad to see this thing raged on during the night..(night for me). It seems it is tuff to tell who I am even debating with anymore....I think a few others are confused too, hell some seem confused at which side they are on! So I will just try to sum up my argument here:
Constant track width is not the goal....the goal is to ski efficeintly with control and performance...in racing efficenancy means fast, for the public it means less tiring and more fun...we generally achieve this by moving as required, when required, no more, no less.
We see some variance in WC tracks, especially those with very high edge angles. This is necessary to prevent being in really akward positions in the transition....hence we may see a WC skiers feet be 24inches apart in the fall-line, then drop to 18 in the transistion. Track width may also vary as a skier comes over a rise, moves into a rhthm change etc.
My issue is with people who interpret this to mean that if a WCer has tracks very from 24 to 18 inches in their best most high performance turns, then it is good sign when they see their tracks go from 12inches to 6. This is simply incorrect.
If you understand why a WC tracks may vary from 24 to 18, then you should be able to understand why your tracks might vary from 12 to 10, but not cut in half. The difference is simply how we are built. At very high edge angles the feet must be apart to keep the outside foot on the snow, this may be wider then is workable in a transition...(Remeber: wider is more stable, but results in less agility)....but we must keep in mind that at 18 inches that is still a very wide stance, and yet it still provides the right balance of stability and agility for the turn......for joe public, it is extremely unlikely they will ever find themselves in a turn that REQUIRES 24 inches of feet separation...if you could make turns like that...you would be on the WC (further: turns like that need things like very very very hard snow to push back on the skier...WC uses water injection in their courses...I grew up in the East, so I thought I new what ice was all about, until I skied a WC slalom...WC combat this with very very sharp skis....5degree side bevels in slalom are common, 3 in GS...)
Hence this extreme angles goes beyond what their bodies can do in the transition, and that is fine, they compensate....but if your stance in the apex is 18...what are you compensating for by going back to 6?...so what causes it?....generally it is caused when a skier holds onto the downhill ski too long. So what does that mean?
By holding on to the downhill edge too long, the dh ski is still edged with pressure and it is still steering across the hill...this pressure comes from resistance to the path of the COM. However wanting to leave the turn the skier does allow the COM to move across...some up, some across...the result is less edge angles and less pressure...which are both effective at making the skis "turn less" and begin to transition....hence what is happening is your COM begins to move downhill and as it does it "pulls" your knees and ankles downhill with it, reducing the edge angles and ending the turn...it doen't do this evenly of course, hence the inside ski loses pressure first and thus tracks straighter sooner, causing the converging tracks.... to ensure that your knees and feet do get pulled over some tension in the legs is required...ie you can just go limp...this causes the "up"...subtle yes...a few inches yes, but a few inches of hip movment is a lot.
I understand this way of skiing will feel great...it will be a very quick edge change as the mass is already inside both feet the instant the new dh ski is edged.
The drawback with this is you are skiing with your body, and using its momentum to pull your feet from one edge to the other....it works...I know, becuase I skied this way for years, and was even able to get my CSIA 3 skiing this way. But be aware that it also gets your tranistion being from apex to apex: 80/20, 80/20, 80/20, 50/50, 40/60, 30/70, 20/80
What I advocate is this....harness the energy built in the fall-line by releasing both skis together....by shifting your weight onto the back of the skis to diminish their self-steering effect...causing them to "turn less" equally. As your skis are straightening, you relax both legs to allow your COM to "flow" to inside your feet uninterruppted....as your COM continues to move acros you are progressivley putting more weight on the uphill ski, while at the same time from the feet up, decrease the edge angles. Hence your transistion from apex to apex will be: 80/20, 70/30, 60/40, 50/50, 40/60, 30/70, 20/80...much smoother and progressive.
Hence one technique begins the tranistion by diminishing edge angles, the other by working the skis self-steering effect. The difference at the end of the day is pretty subtle. One uses your mass to pull the skis off edge, up and over to start ending the turn...the other uses the self steering effect, then with relaxing both legs evenly lets the COM flow, and the edges are then reduced from the feet.....
The second one is definatley higher skill, and following from what people say it sounds like PMTS advocates the first scenario (if i am wrong on that fine...), which makes sense as it is easier and effective for most people...but if you want to step up to the big game, then you need to get more technical.
To sum up, real world means that tracks converge and diverge, but the less you have means you were closer to scenario 2...which is more effiecient, as it allows your COM to flow, and promotes skiing from your feet, as opposed to working with the COM, effectivley having the COM control the skis...of course at WC level, some of the extremes force you to take into account some limitations of the human body...but that rarely applies to 99% of us.