Perfect calibration Overconfident model Overconfidence gap
A well-calibrated model's accuracy matches its stated confidence at every level. An overconfident model overstates its certainty throughout — at 80% stated confidence, it is correct only 61% of the time.

The gap between the curves is miscalibration made visible. At 80% stated confidence, the overconfident model is correct only 61% of the time. A well-calibrated model closes that gap entirely.