[luckylion]

How does the sorting work on Youtube? It's not by upvotes, it's not by date, it's not any obvious combination of the two (as newer comments with more upvotes can still be sorted after older comments with fewer upvotes). Them using a hidden total-like-count might be an explanation.

[frosted-flakes]

If you don't surface newer comments all the upvotes will skew towards older comments. I expect there's an element of randomness. Number of replies, whether the uploader put their badge on it or replied are probably also taken into account.