In reply to Petra.

I'm so pleased! Even better, I did another chin-up today, so I know it wasn't just a fluke!

Pull-ups are apparently still a ways off. I'm tweaking the way I do my negative pull-ups to see if I can get over the hump. Specifically, I'm doing them much more slowly, trying to concentrate on the phase where I shift between traps and lats.

I'm also trying to do some shoulder circles (moving my shoulders back and down) while hanging from the bar.

Both of these are aimed at helping activate my lats while pulling. I was surprised to find that my traps were really sore after my first chin-up, whereas I didn't feel it in my lats at all, making me think that I'm not much using what ought to be the main muscles for pull-ups.