With a continuously running clock do one pull-up the first minute, two pull-ups the second minute, three pull-ups the third minute… continuing as long as you are able.
Use as many sets each minute as needed.
Post number of minutes completed to comments.
“The squat, press, deadlift, and bench press have been used for decades by the strongest athletes on the planet. There is good reason for that. Any program that doesn‚Äôt use them is inferior to one that does, and any athlete who neglects them is doing less than that is possible in his performance, and less than what is absolutely necessary to maximize his strength.” –Mark Rippetoe