This strategy is the most exotic – it’s a mix of rebase and a merge. First, the commits in the pull request are rebased on top of the master branch. Then those rebased pull requests are merged into master branch. It emulates running
git rebase masteron the pull request branch, followed by
git merge pr --no-ffon the master branch.
Some people think of this as the best of both worlds: individual commits are retained, so that you can see how the work evolved, but instead of just being rebased, a “merge bubble” is shown so that you can immediately see the work in each individual pull request.
Taken from Pull Requests with Rebase