

Netflix Prize Update: New Team in First Place (deadline tomorrow) - larryfreeman
http://www.netflixprize.com//leaderboard?limit=50

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gtzi
The Ensemble is actually a meta-team of most of the teams that didn't
participate in BPC, and I'm hearing that BPC had lately tried to get some
other teams to join, so they were kinda expecting that (but I don't think they
will be able to fire back). Bottom line, I think that the most massive open
data set out there (next to a competition) has really helped the research to
move on, but I don't see the point in 5 or 10 teams joining forces to improve
the results for a tiny percentage and win the prize. On the other hand, maybe
this is actually the right thing, for all these teams that have struggled for
two years to be in the top-15 to receive the prize...

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rudyfink
> I don't see the point in 5 or 10 teams joining forces to improve the results
> for a tiny percentage and win the prize.

I think the point is who gets the million dollars. It makes sense that people
would group up, probably into as few additional participants as it would take
to ensure winning. If you and I were in the vicinity of being able to win
independently and we knew we would lose otherwise, I think we have every
incentive to team up.

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IgorCarron
Shouldn't a new result above 10 pct reset the clock with a new one month
period ?

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slackenerny
From the rules: <http://www.netflixprize.com/rules>

_When the RMSE of a submitted prediction set on the quiz subset improves
beyond the qualifying RMSE an electronic announcement will inform all
registered Participants that they have thirty (30) days to submit additional
candidate prediction sets to be considered for judging. At the end of this
period, qualifying submissions will be judged (see Judging below) in order of
the largest improvement over the qualifying RMSE on the test subset._

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markbao
One thing's for sure: BellKor's Pragmatic Chaos is going to get shitfaced
tonight.

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Raphael
Trying to hit the Ballmer Peak.

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markbao
BK/PC submitted their last RMSE 2009-07-25 15:53:34, three hours before The
Ensemble. If they can hit the Ballmer Peak or otherwise beat the Ensemble RMSE
before tomorrow morning, it should be very interesting.

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Herring
Aren't you only allowed to submit once every 24 hours or something?

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hvs
Yes, you have to wait 24 hours from your last submission.

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Herring
Anyone know why blending seems to work so well?

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hundredwatt
It seems like just a consequence of basic statistics (central limit theorem?).
Any algorithm you create has some random bias. By blending, you take several
algorithms with random bias and average them together, reducing the overall
bias (assuming the algorithms converge toward the correct result).

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eru
That's as far from the central limit theorem as you can go..

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trapper
Wow, the second team will be gutted!

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harknesslabs
If BPC didnt expect this to happen they deserve to lose. They should have
expected a last minute submission and have one for themselves also.

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hvs
Reducing the RMSE isn't quite that simple. Teams have been working for years
to improve the algorithm by 10%. You can't just "boost it up" in order to win.
It takes serious work. BPC is still working to improve their algorithm like
everyone else but questioning whether they "expected this to happen" is
ridiculous. None of the top teams "deserve to lose", they've all done great
work and deserve a round of applause, regardless if they are the ultimate
winner.

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gojomo
Is there any rolling-extension each time a new top submission arrives -- like
in some auctions -- or is the deadline firm at X days after the first +10%
entry?

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elq
no. it's over tomorrow morning at ~11:30am PST... there are a few
complications that could cause an extension, but they're not likely.

