video proof-wise blow d pay nis is the king on this forum.
he told me to 3x3 2-3x per week adding no more than 2.5lbs every time. but only add if reps are crisp and not forced.
worked so far for me.
though if you know elitefts.com, harry selkow the "pullup guy" there told me that the above method is ok towards achieving a limit chinup weight which my goal at the moment is.
although he said he does
3x3
4x3
5x3
5x4
5x5 with the same weight then add, then repeat.
but bear in mind that there is no written literature for chinning greatness (correct me if i am wrong) probably because it is just an assistance lift so why worry about programming it for maximal weight. just experiment on your own and see what works.