[Timothee]

What would be interesting to see would be merged vs. open vs. closed (as in rejected), and also the typical delay between the opening of the PR and the merging/closing.

Some projects are fast to close PRs if they don't fit their goals, some don't attend to the PRs at all and you have PRs lingering in the queue forever.

Two projects could have a similar acceptance rate with very different attitude: one could be on top of things but picky about what they merge in, while another is just not attending to the list except for the odd PR now and then. It seems that a project like the former would still be more interesting to participate in just because you could expect more feedback on what is wrong.

Regarding the presented data, I'm also surprised that it's that high for some project. With the way GitHub works, it's easy to create a pull-request without consulting anybody in the original project, so it's surprising that so many would match the projects' intentions.