Performance means more than one headline win percentage.
A prediction system can look strong over a long period while still producing unstable stretches. Diamond Forecast therefore tracks accuracy alongside calibration, probability error, daily volatility and separate parlay-leg versus ticket outcomes.
Accuracy and calibration
Straight-up accuracy is useful, but it does not tell whether a 70% prediction is truly more reliable than a 55% prediction. Calibration buckets, Brier score and log loss provide that additional evidence.
Daily stability
Daily and rolling-window performance are tracked so clusters of weak slates cannot disappear inside a season-long average.
Parlay legs versus tickets
Every parlay leg is graded as an individual model decision, while the whole parlay ticket is graded separately as a construction decision. A three-of-four losing ticket therefore still contributes four model observations.
Important: Diamond Forecast publishes probabilities and model analysis, not guarantees. Sports outcomes contain real uncertainty. Qualified picks and parlays can lose, and users should never wager money they cannot afford to lose.