The $1M Winner's Secret: 107 Algorithms
2009: Netflix Prize winner announced
BellKor's Pragmatic Chaos wins $1 million
Their solution: Not one perfect algorithm, but 107 different algorithms blended together
Each algorithm votes:
- Collaborative filtering: 0.82 confidence
- Content-based: 0.75 confidence
- Time trends: 0.68 confidence
- Recency bias: 0.71 confidence
- Device type patterns: 0.64 confidence
Final prediction: Weighted average of all votes
The lesson: Combining approaches beats perfecting one approach. This is called ensemble learning.