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baseline
The dumb method you have to beat: predict the mean, the last value, or the rule you already run.
What is baseline?
A baseline is a simple, honest comparator. If a model does not beat “always predict the majority class” or “repeat yesterday,” it is not earning its complexity. The baseline uses the same split and the same metric.
Why does baseline matter when vibe coding?
Models report 92% accuracy on a problem where 91% of rows are the negative class. Name the baseline before the architecture.
How do you do baseline?
Write the baseline first. Same metric, same split. The new model must beat it by enough to matter. If it does not, ship the baseline.
How do you ask a model for baseline?
Implement the baseline first: (majority class or last value). Same split, same metric. Do not add a model unless it beats that baseline on the holdout. Report both numbers.
What goes wrong with baseline?
A baseline you crippled so the model looks good. The baseline should be the thing you would actually ship.