The Brier score becomes inadequate for very rare (or very frequent) events, because it does not sufficiently discriminate between small changes in forecast that are significant for rare events.
I guess it’s more probability-centric than odds-centric.
OK, so basically it’s well-known that this only works for predictions that aren’t super rare, so it wouldn’t be used to score things that only happen 0.1% of the time on average (which is the only way anyone could be 99.9% accurate).
From Wikipedia:
I guess it’s more probability-centric than odds-centric.
OK, so basically it’s well-known that this only works for predictions that aren’t super rare, so it wouldn’t be used to score things that only happen 0.1% of the time on average (which is the only way anyone could be 99.9% accurate).