THE PLUMB-LINE

A plumb-line tells you whether a wall is true — not whether it is tall. This one tests whether a model's confidence is true to its accuracy. The stream is overconfident; drop the plumb-line (temperature) until the wall reads straight.
LIT ECE / MCE & the temperature fit, computed live   FIG a labelled toy logit field   WALL a real bake under shift
SELF-CHECK running…

Reliability diagram — eval split

accuracy per bin   mean confidence   the gap  ·  the dashed diagonal is the plumb-line (perfect: conf = acc). Bars below the line = overconfident.

Live readout — eval split

Negative log-likelihood vs T

Fit on the calibration split (NLL is convex in 1/T, the inverse temperature). The dot is the minimum; the dashed line is your current T. Accuracy does not appear here — T can't move it.