Well, the thing is I don't know what my max was before I started doing weighted work last summer. But it seemed like it helped and I did 17 chinups a year ago. This year I only did 16 (at the state fair, lol), and, tbh my form could be stricter.
Anyway, the biggest difference in my memory was that last year I felt I just shot up on maybe the first ten reps, like out of a cannon. Now, maybe it is b/c I was less weight a year ago but I think it was also b/c I hadn't done any bw chins really, I was only doing +10 to +25lbs reps. The last year I've gotten away from weighted work until recently and felt I haven't progressed much.
Although, I did use a weight belt yesterday for the first time and was able to do a rep at +90 so I still have a pretty good baseline,
. But if I decide to concentrate on chinups/pullups I'd probably make my core routine weighted once or twice a week and then do other days of bodyweight stuff not to failure. Actually, what I'd start with is doing pullups instead of chinups. The difference between them for me is enormous, makes me think I'm really just doing curl-ups, b/c I'm all biceps, lol.
Please keep in mind I'm just making this up
. Also, Evoken and RealBusto do a lot of weighted work and they are likely the pullups champs here. FakeBusto seems to be doing plenty of weighted work too and he seems like he may also be able to do a ton of pullups.