I built WinOnly to see if a fully transparent, rule-based approach could produce reliable football match predictions. The engine analyses league standings, recent form, and defensive stats across 29 leagues to pick up to 10 match winners daily. Every rule is published on the site — you can see exactly why each pick was made, and results are tracked automatically. Built with React, TypeScript, Express, and PostgreSQL. Would love feedback from the HN community, especially on the methodology and data approach.