When I was taught my kata originally, no one made a point about the starting and ending point of the kata should be the same spot.
A few years later I read this in the books by Funakoshi Ginchin, that this was the desired way to do the Shotokan kata.
But then when I studied with an instructor teaching Shotokan, this was nothing I recall was discussed.
A separate but related idea that I began to work on, was I came to appreciate stances and the manner of stepping even more as time passed. For one thing I became fascinated with the potential applications from the manner of stepping and the stances employed.
Then one night I decided to look at how close the kata I did with my Isshinryu were to that standard. What I found was the kata did start and stop on the same point for me for the most part.
But while the manner of stepping and stances became a focus of my teaching, performing kata to start and stop on the same point, was not something I worried about.
Among which I did not recognize any variation of the stances for kata. A Seisan Stance was to be the same Seisan Stance every time. Likewise the use of the crescent step was the only method of forward movement I taught. My reason was I cannot recall ever being told anything else was the way to step when I learned.
Now roll a few decades forward.
My adult classes were small, and frankly I was often less than I could have been as an instructor, too often using kata practice for my own practice.
Becoming disabled taught me many things. No longer able to perform most of the class, I instead was watching what was happening much more. And seeing much more too.
One evening my senior students, Mike and Young, were working on Wansu kata. They had very good technique, extremely good execution. They showed they understood what the movements were for in their practice.
But this time watching I saw something else. As they did the kata, they were gradually moving forward. Ending well in advance of where they started.
I understood what they were doing, so I had an idea. I issued a challenge.
At the back of the class we has a mat on the flool from the wrestling program.
It had a large circle impressed on it, and there were two parallel lines in the middle to allow the wrestlers to start their matches from.
Those two parallel lines were to be my challenge, the starting and ending point which I would perform Wansu kata from.
So I did my kata, and started and stopped in the same place, when I did it.
Then I challenged them to do the same.
They did their Wansu kata. In fact several times each. And each time they did it they moved forward, ending well in advance of where they started.
Only then did I explain the difference. What they were doing with each kick is putting their foot down well in advance of where they started that kick. So each techniques was moving them forward.
When I did the kata, as I concluded each kick, I put my foot directly down as it I had done one crescent step forward. That was the difference enabling me to keep my kata footprint smaller. And which I felt was more consistent with the application potential I wanted with the form.
Now their kata performances were fine, powerful and sharp. They were just doing something else from what I was doing.
I believe this explains were some kata creep, or movement of kata performance, comes over time.
Even slight variances of the original goal, ends up changing the kata. Not so it does not have value, just a different value than what was originally intended.
Other thoughts on Wansu kata;