If anyone is having trouble with chin up/pull ups, here is a program I set up for a friend of mine that has worked out well:

Do them twice a week at the beginning of the workout.

Workout A: do one set of max reps (must be at least 6 reps) either BW or with added weight

Workout B: add 50% to the total reps from your max set during workout A and do three sets that will add up to that number .

For example, workout A your max set was 8 reps. 8 reps + 50% is 12 reps, so for workout B you would do 3 sets of 4 reps ( 3x4=12). This will be challenging but not hard enough that you will hit failure on any of the sets.

If you end up hitting an odd number like 9 for example, just round up. 9+50% is 13.5 so just round up to 14, and on workout B do 3 sets of 5,5,4.