• www.youtube.com/watch?v=-_qNKbwM_eE Unsolved: Yang-Mills existence and mass gap by J Knudsen (2019). Gives 10 key points, but the truly hard ones are too quick. He knows the thing though.
Video 1. Yang-Mills 1 by David Metzler (2011) Source.
A bit disappointing, too high level, with very few nuggests that are not Googleable withing 5 minutes.
Breakdown:
Video 2. Millennium Prize Problem: Yang Mills Theory by David Gross (2018) Source. 2 hour talk at the Kavli Institute for Theoretical Physics. Too mathematical, 2021 Ciro can't make much out of it.
Video 3. Lorenzo Sadun on the "Yang-Mills and Mass Gap" Millennium problem. Source. Unknown year. He almost gets there, he's good. Just needed to be a little bit deeper.