This is by far the simplest of all pullup programs, but do not let the smooth taste fool you; this is an epic program. In fact, its how Arnold Schwarzenegger achieved his magnificent results.
Do as many good reps as you can on your first set, say 10
In the next few sets your reps will fall, perhaps to eight on the second and five on the third, which now totals 23 reps.
Continue to add reps until you’ve reached 50.
Very simple, very tough.
This workout will smoke you. Do not try it more than once per week! After a few weeks, you will be able to knock out twice as many pullups as you were able to before. Stay with it, and 50 pullups will be achievable after 6 months with ease.