Average tracking performance can conceal a catastrophic outlier: a controller with one huge error may be as bad as one that wanders slightly, such as a robot striking someone on the head.

“But so on average something which tracks it perfectly and has one huge uh error where kind of the robot clocks you on the head is completely the same as one thing which kind of just slightly wanders around. And in fact this is this nice paper about uh what was it called like deep reune ex uh training deep reune networks to uniform accuracy is intractable or something like put into Google, you'll find it. But”