There are a lot of former pantsers who become really different writers by participating in the Prep. Wonder why? One of the things in changing your perspective is learning the arc. It's like the practicing something before you break the rules.

Have you seen builders put a house together without a blueprint? It can be done, but it might not be as pretty, as complex. (Some writers totally manage, though.) Allowing your brain to try to create a blueprint, even if it changes a lot during November, is a central idea to the Prep. We're spending time with that novel so we don't just end up with three chapters and getting blocked. We're giving ourselves an opportunity to see a map of the entire project.

Have I had this thing and then found the characters went in a different direction because that's just who they were? YES. Have I put it into this and then figured out the one character didn't work and needed to change? YES. But would I have known that if I jumped in November 1? Maybe not- and those can be such big game changers as to throw us off the novel track entirely. Remember it is your book and your choice - and the plan we put together may not be what you follow in November but it helps your brain be able to envision larger plots and subplots and other structures within to make your book better - even if you end up pantsing in November.