Netflix Awards Contest Prize and Announces Second Contest

In October 2006, Netflix issued a $1 million challenge to improve Netflix’s recommendation system, the system that recommends films to members based on their past ratings of films, by 10% or more. It gave contests access to 100 million anonymized movie ratings and asked them to predict the tastes of Netflix members.

The final hours of the competition saw two teams, The Ensemble and BellKor’s Pragmatic Chaos, fighting for the number one spot, as both had surpassed the 10% minimum. 24 minutes before the end of the competition, BellKor’s Pragmatic Chaos made a final submission that put them slightly ahead of The Ensemble and allowed them to win the contest, which ended on 29 July. It then took a group of judges several weeks to validate the winner.

Today, Netflix gave BellKor’s Pragmatic Chaos, which is made up of three groups that previously competed against each other and includes Bob Bell, Martin Chabbert, Michael Jahrer, Yehuda Koren, Martin Piotte, Andreas Toscher and Chris Volinsky, the $1 million prize for their work. As per the contest’s rules, the team will publish their method and the hidden ratings used to determine the winner will be made public at the University of California Irvine Machine Learning Repository. Their work has been licensed to Netflix and can also be licensed to other companies.

Also announced was a second contest, this time challenging participants to generate accurate recommendations for members who seldom rate films by taking into account the members’ ages, genders, ZIP codes, genre ratings and previously viewed films. Participants are given access to 100 million anonymized data points that cannot be associated with a specific Netflix member. This time, Netflix does not have a specific improvement goal because it cannot predict how well the information can be used to generate accurate recommendations; therefore, $500,000 will be awarded to the contestant that is ahead in six months and another $500,000 will be awarded to the contestant in the lead after 18 months.