Sports Betting Model question
Built a walk-forward jockey/trainer/OR/RPR/TS Elo model on UK racing (Betfair archive + Kaggle raceform, verified to 94.9% match), properly avoided lookahead, still can't beat the closing line even with the richer data. What do serious horseplayers use that public ratings data doesn't capture?
I tested favourite-longshot bias split by home/away favourite status in football/basketball/hockey/rugby league — turns out almost nobody's published this specific four-cell test outside the original 2009 football paper. Anyone tried it informally and found it's a dead end in a particular sport before I sink time into it?