We had a (small) Hacker News fantasy league for March Madness last year -- the only rule was that your picks had to be by some algorithm which you shared after everyone made their picks. I'd be happy to set up one for this year if there's enough interest.
That sound fun. I think the rule should be a bit more hardcore, though: that the predictions have to come from raw data. i.e., no meta-algorithms that use information about seeding or expert predictions, but if somebody wanted to gather, say, play-by-play data and use that, it'd be ok.
