How to disable default branch being the default target branch in a pull request

[Sineth Jayasinghe]

We operate in an environment where there are a lot of branches, when I try to create a new pull request, in my case by default the 'master' branch becomes the target; This is not the target branch I'm looking for 99.9% of the time. Also, this tries to create a diff of commits being populated to the description section which I have to clean up too. 

Is there a way around this to make sure that the master branch is not preloaded in each and every new PR I try to raise?

[Deepesh Nellutla]

You can  also set the main branch ( the one which you want to merge every time a PR is raised) by going under Repository Details and select Advanced Section. Choose Main Branch dropdown.

[Esther Strom]

The default branch is set at the repo level; if you're a repo admin you can change it. Go to Repo Settings -> Branching Model: