This is good in the sense that having poorly calibrated forecasts is bad, but it's not quite as strong as you might want it to be. Imagine that you're tasked w

This is good in the sense that having poorly calibrated forecasts is bad, but it's not quite as strong as you might want it to be. Imagine that you're tasked with predicting the next state of a traffic light that just cycles through green, yellow and red over and over again. If at every step you forecast that there's a 33% chance of each color, you have a very well-calibrated forecaster, but it's clear that you can do better. FiveThirtyEight probably actually is doing better, but I suspect that they're not choosing to highlight those stronger metrics because they're complicated to explain.