ping
FIXME GBRT: better explain log-loss
FIXME: add example of calibrated and inaccurate vs accurate but not calibrated!
FIXME: calibration: what are the estimators fit to, and why does fitting it to 0 and 1 create probabilities in between

Partial dependence plot. how is that different from feature importances.
calibration curve plotting: bins are different for hist and calibration curve?
slide 27: maybe put probabilities on x axis?
calibration curve: blue histogram is number of total points, y axis not la