$1M Netflix Prize goes to BellKor’s Pragmatic Chaos

September 21st, 2009

Netflix announced today that BellKor’s Pragmatic Chaos team was awarded the $1M Netflix Grand Prize.

“It is our great honor to announce the $1M Grand Prize winner of the Netflix Prize contest as team BellKor’s Pragmatic Chaos for their verified submission on July 26, 2009 at 18:18:28 UTC, achieving the winning RMSE of 0.8567 on the test subset. This represents a 10.06% improvement over Cinematch’s score on the test subset at the start of the contest. We congratulate the team of Bob Bell, Martin Chabbert, Michael Jahrer, Yehuda Koren, Martin Piotte, Andreas Töscher and Chris Volinsky for their superb work advancing and integrating many significant techniques to achieve this result.”

Netflix announced that it will hold a new Netflix Prize 2 contest with details to be released.

What about the Ensemble’s last-minute entry, the one that seemed to top BellKor’s?

“Team BellKor’s Pragmatic Chaos edged out team The Ensemble with the winning submission coming just 24 minutes before the conclusion of the nearly three-year-long contest. Historically the Leaderboard has only reported team scores on the quiz subset. The Prize is awarded based on teams’ test subset score. Now that the contest is closed we will be updating the Leaderboard to report team scores on both the test and quiz subsets.”

As part of the final submission, teams were required to submit papers describing the approach. Here are the three that the winning team delivered.

The New York Times Bits blog also has an article, Netflix Awards $1 Million Prize and Starts a New Contest.