Jun 9, 2026
12 min read
> kairox tempo
Log-Loss Is Not Enough: How Identical Scores Hide an 11-Point ROI Gap
Seven XGBoost runs on the same La Liga dataset land within 0.0025 log-loss of each other. Their away-betting ROI diverges by 11 percentage points. Walk-forward evidence that the metric you are optimising is not measuring what you think.