A few christmases ago I was messing about creating bubble maps - no doubt in some mince pie and port induced state of inebriation (quality of code is consequently as you'd expect).
I'd long forgotten about this until Kent Becks recent post on medium.com about trying to understand A Year's Worth of effort.
This looked familiar and so with a little manipulation here's a simple utility to convert priority ordered stories into a visual bubble map.
Provide story information in priority ordered CSV format (<points>,<story-name>) to display map.
Name is optional.
Velocity: points per sprint.
Estimating ... sprints to complete ... points across ... stories.
Optimal duration is ... sprints.