Accuracy & evaluation

Baseline forecast

A baseline is a simple rule you must beat: last value, last week, last year, a seasonal naive, a moving average. If a fancy model cannot beat it on a fair backtest, keep the rule and save the drama.

Baselines are not dummy work. They are the price of admission. Vendors who will not publish vs-baseline numbers are selling a chart.

Pick the naive that matches the clock. Last-year-this-week is a high bar in retail. Last-hour is a high bar in energy. Using the wrong naive makes everyone look like a genius.

A baseline should run in production too, as a watchdog. When the champion loses to last week for three origins in a row, something is stale.