seaborn.barplot — seaborn 0.13.2 documentation:

passing order=[list,of,cats,in,order] decides the ordering.

Otherwise “it will be inferred” except that it’s not always trivial to understand how exactly (or I’m too sleep-deprived).

And if I’m drawing horizontal lines on top of the bars in the barplot based on indexes then the order may be sligthly different.