Back-counting (Wonging) doesn't work.

[10JQKA]

TC is calculated as RC over decks remaining. If you have a count of +10, as you continue deeper, both the magnitude of the numerator and denominator will decrease. As a result, the TC will have a tendency to stay the same, not revert to zero. This makes sense as the TC indicates the richness of the remaining cards and there is no reason to believe the richness will decrease. On average, the excess tens will be evenly distributed.

I understand this part but if the true count reverts to and becomes 0, so does the true count, regardless of how many decks left. I think perhaps I have been looking at this too black and white where as obviously the RC changes more erratically than the TC and that a table full of low cards may drastically move the RC a lot closer to 0 without chaning the TC, especially at the start of a shoe.

I think I have grasped this concept now, thank you for your help with this.