"We must endeavour to keep the hand in that (natural) position at all times, moving it along quickly and easily to the next position – 'displacing' it from one group of notes to the next. That is one of the basic secrets of piano technique"
I instantly went to my piano and tried Chopin's # 1 Etude in C major using this displacing of the hand to the next position without stretching: It was a MIRACLE!!!!!!!!. It worked like a DREAM: No tension, no stiffening, no tiring of my hand... It felt so easy, so non-straining. I could go on playing the piano using this principle for ever without feeling any stiffening, etc. God must have spoken to you when you discovered this phenomenon. My gratitude to you is INFINITE. I cannot wait to read the rest of the advice you have in your book on piano technique.
Since I am a physician (neonatologist), your applying anatomy and physiology to explaining piano technique is a total BLESSING: It makes the principle easy to understand.
THANK YOU, THANK YOU, THANK YOU, DEAR ALAN…
P.S. "Displacement", among other things I learnt from your book WORKS, every time – thanks. zu