Verification of forecasts expressed in terms of probability

Main finding

Introduces what is now called the Brier score, which rewards forecasts that are both well calibrated and sharp.

Limitations

A scoring rule, not a betting test; it does not measure profitability.

Study details

Authors

Glenn W. Brier

Published

1950

Venue

Monthly Weather Review 78(1), 1–3

Status

Published

Evidence type

Peer-reviewed methods

Evidence strength

Strong (our assessment of how much weight the finding can bear)

Sport

None (weather forecasting)

Markets

None

Method

Proposes a score for verifying probability forecasts: the mean squared difference between forecast probabilities and outcomes.

Sample

Not applicable.

Replication

Standard method.

Read the original

doi:10.1175/1520-0493(1950)078<0001:VOFEIT>2.0.CO;2 (opens in a new tab)

Our summary is an original paraphrase for education. Verification: Bibliographic record checked against consistent citations; the publisher page was not reachable. Checked 2026-10-25.