Binary Event
A binary event has exactly two outcomes, usually yes or no. Brier score and log loss are commonly used to score probabilistic forecasts for binary events.
Definition
A binary event is an event with two possible outcomes. In forecasting, it is typically represented as:
• Yes (the event happens, outcome = 1)
• No (the event does not happen, outcome = 0)
Examples
• Will a team win the match?
• Will inflation be above 3% on a specific release date?
• Will a candidate win an election?
Why it matters
Many prediction market contracts are naturally binary. That is why Brier score and log loss are widely used: they score probability forecasts against a binary outcome.
Related
Binary events connect to implied probability and to market pricing via market consensus.