OK, I think we all agree that Mark isn't as fleet-fingered as he used to be, due to age and who knows if there's some arthritis or other stuff going on. The cold certainly doesn't help. Then there's the fact that he has done it all, several times over, so to expect him to be really excited to perform and pour a ton of emotions into his playing, well, we might have to adjust our expectations. We certainly can't blame him for any of this. I'm guessing, he probably could practice more guitar to keep his chops up, but if he's not really into it, then what's the point. The guitar hero thing is old hat to him anyway.
cold obviously doesn't help but this was a very short perfomance, few minutes of playing in a very slow song, not a full concert, it's really ingenuous to think cold is the issue here, especially after an avalanche of errors in the 2019 tour
I'm pretty sure that Mark suffer from some degenerative disease or a Parkinson variations.
Since 2013, seeing some tour videos, its cleary that Mark has tremor in his hands. Probably he uses a lot of medications so he was abble to play without major problems. Not the guitar hero that he used to be, but with strong hands.
During the passing years, he barely play a decent electric guitar but he was abble to play some acoustics very well. Observing the Brian Johnson interview, Mark almost didn't play the guitar during STP or any song. Just bad playing and fractions of songs.
In other recent interviews, Mark was hiding his hands or holding his leg almost all the time. Based on my observations, i believe that he loses his fingers strenght. For me, the proof of this was the DTRW album. He play mostly electric because he cannot play acoustics properly. Matchsick Man is not well played.
During the 2019 tour, he barely can play R&J or TR. Of course that was some good moments during Speedway and Why Aye Man. OUATIW was a disaster.
But our hero keeps his passion to the music and refuses to stop playing. But nowadays, for him, the art of playng guitar is very hard to achieve. Even if he practices guitar every day, this fisical condition is a nightmare.
Sorry about my poor english.