To give you even more courage: I make all the time mistakes! 😄 We see on concerts, recordings,…the results. But during the process, the behind-the-scenes, we fail so much!

^ I’m certainly not Laporev here, but, thumb position may just be one of those things you find yourself needing to use out of sheer necessity rather than a daunting obstacle to be overcome. Certain passages in the higher registers are simply impossible without thumb position. It’s also definitely suggested you not self-learn (you could be building bad habits and poor technique) and find a teacher you can afford and work with well. I began learning thumb position by simply shifting (Feuillard exercises) to positions which required the thumb to be out from behind the neck, though not necessarily stopping the string. Then gradually I learned (and am still learning) shifting to the thumb itself to stop a note. After that came being mindful of the proper left hand shapes when we’re in thumb position as cellists. This is still a little tricky for me. I used/am using Feuillard daily exercises, Yampolsky scales in thirds, sixths, and octaves, and of course Popper’s High School of Cello Playing, which is considered ostensibly the cello bible among many players.

I use to think „thumb position is not more difficult. It is just less practised“. This helps me.

I am sorry if I offended. I am guilty of every sin that I accuse you of, in spades. The time and Zen-like discipline required to truly achieve "perfect" slow practise, free of anxiety, is rare for a busy musician, and we inevitably fail to one degree or another. Nevertheless our attempts are valuable and lead, as you correctly point out in the title of this wonderful video, to progress. I certainly rarely achieved perfection in my own longer but less illustrious career than yours. (I'm retired now and never play cello anymore). One of my most memorable practise sessions was fifteen minutes one lunch hour between orchestra rehearsals, when I practised simply placing the bow on the D string at the frog focusing my attention on the visceral sensation of; the hair's engagement with the string, the stick's engagement with the hair, my hand's engagement with the stick, my arm's engagement with my hand, my body's engagement with all of this including I daresay the chair and the floor, and my mind's engagement with the universe, so to speak, lol. I recognize the honesty and humility in your acknowledgement of your unwanted vibrato and am ashamed that I felt the need to humiliate you further with the tone of the previous comment. I don't deserve but do nevertheless hope for, your forgiveness. Not here in KZfaq comments, but in your heart. You play absolutely beautifully. (I confess I do prefer my own playing, or at least what I remember of it, but I think as artists we all love our own art most, are our own biggest fan... or we should. I hope you're your own favorite cellist. I doubt this is a vain hope.)