Why do releases affect burndown? Is this a config setting?

[Damien]

I am not sure if this is a config setting, or just how "JIRA Works", during a sprint, as features are completed, we will do a release mid sprint, potentially releasing 3 - 7 times a sprint however I am finding, once issues are released and come off the board, this is affecting burndown charts, and finding it difficult to get a good understanding of burndown and thus velocity for the team. 

[Damien · Accepted solution]

All good now, I think I have worked it out... we had a filter on our board, which excluded released items.  Thus, once released would be removed form the board, and affects burn down. 

So it seems, the burn down is very much tied to the filters applied to the project boards.