10:1 rule

I've often wondered why programmers are so bad at estimating the time and effort needed for a task. (An old Product Manager friend of mine used to say "ask a programmer for a pessimistic estimate and then multiply that time by two.) Yevgeniy Brikman offers one possible explanation: The 10:1 rule of writing and programming. Looking at git checkins for both his books and some popular software projects, he sees each line being rewritten at least 10 times, statistically speaking! And an update at the bottom of the article points out forum talk saying similar guesstimates of 10:1 apply in film, journalism, music, and photography.