I was taught the "5 points of contact" years ago while working for a former Fred Astaire studio, but have since developed my own variation.
First, I no longer refer to them as "points", because none of them are single points. They are all really "areas", especially that of body contact. So I'm very specific about describing "areas", not "points" of contact.
Second, I now only refer to four areas. I'm not a fan of describing the position of the lady's left elbow as being in contact with the man's right elbow. In almost all circumstances the lady's left elbow extends farther out than the man's, which means the lady's elbow itself is not in contact. More importantly, it's unnecessary (and actually in some ways, detrimental) to describe the hand and elbow as two separate points of contact. For me, the lady's left hand and entire forearm represent one single area of contact, which are connected or disconnected together.
Ladies who are taught to connect the hand and elbow often lift the wrist, resulting in a distorted arm position as well as an unnecessarily strong left hand grip. So I talk about the connection of the entire forearm and hand without any gaps, to the point where the end of the arm extends beyond the man's. This makes one single area of contact, leaving us with only four total.
My question is how much of the lead is coming from the area of the chest with todays dancers.
Impossible to quantify. It's shared between all points of contact. We would hope that a majority of the lead is in the body, as alll movement starts from the center. But the other areas of contact play a role, or they would not serve a purpose. I think of them as senses -- you can lose a couple of them and still function.
What makes body contact unique is that it is both the largest area and the closest to the center of mass. As a result, it is the most reliable and also the most sensitive. Great standard dancers can do a lot of leading without any of the other areas of contact (though without at least one other contact area, there are limits to what even the world's best can do in an imorovised setting).
The world's best competitive American style dancers are also experts at leading with single areas of contact
other than body contact. For example, one can do amazing things with only the man's right hand to lady's shoulder blade, or only the man's left hand to lady's right hand. But because these are farther from center of mass, with many joints in between, the margin of error is greater, and more weight is required. Whereas body contact can be effective while feather-light, other areas of contact used solo require some counter-weight before any reliabe communication can be established.
In other words, once you take away body contact, connections typically need to be stronger -- not through muscular force but through use of counter-weight (eg "push" or "pull") to be effective as instruments of lead & follow. The fewer points you have, the more counter-weight you'll need, to the point that if you're standing apart with only a LH-RH hold, you're basically using Latin leading & following technique.
This may be more information than a standard dancer wants to know, but in a roundabout way it still pertains to them. At the very least you should realize that all areas of contact serve a function beyond the aesthetic, though none is absolutely necessary at all times and can be compensated-for by the others. Like senses, when one is lost, the others increase in sensitivity to make up for it.
Standard dancers rely on body contact because is it the most simple and reliable area of contact, the one that requires the least amount of effort through which to communicate. But don't make the mistake of confusing "most reliable" with "necessary". There is nothing necessary about body contact, other than the fact that it is mandated in competitive dancing by an arbitrary rule. Take away that rule, and you learn how to blend Standard and Latin lead & follow techniques, a skill that has become the hallmark of expert American smooth dancers.
Regards,
Jonathan Atkinson
www.ballroomdancers.com