The amount of Jeopardy! questions that are online in J!-Archive is by now quite large. So large that it has begun to approach the corpus of facts from which knowledge-based non-current-events Jeopardy! questions are drawn.

Although Jeopardy does not repeat questions per se, they often find different ways to clue the same fact or connection.

I would guess that if you took the text of a clue, ran some trivial clustering on the J!-Archive contents, and instantly displayed the top three clues and responses for a human, they could be quite competitive on the show even if they knew nothing on their own.

So if you put the J!-Archive into a Leitner-system flashcard app and put a few hundred hours into it, I imagine it would improve a contestant's chances considerably. It doesn't look like much, but that looks like the major tool here. If I had won my last game (the final regular game of Season 23, followed by a six-week hiatus) I was planning something like this. However, I never thought of using analytic feedback with categorization in this way. That clearly also gave him some valuable feedback on what to study and what categories to be confident about.

However, this is to take nothing away from Roger Craig's exceedingly impressive untrained skill at the game, which he was able to train effectively to unreal levels. He plays Jeopardy! like a boss.

I think the big innovation highlighted in the video is that he used historical data on frequency of certain topics, the dollar value assigned to those topics, and his personal performance on certain categories to figure out which categories were most important to study. I know that I am bad at fashion and 19th century French literature but what relative fraction should I spend on one over the other? His code gave him a number and that's the ratio he studied them. So you're right, at that point it's not much different from flipping through a giant study manual, other than the manual telling you should should really look at pages 3, 11, 21, 47, 96, ... because that's what the solution to the nonlinear optimization problem said would give you the best chance at winning against simulated opponents.

There's a video of Roger Craig explaining the web app he created: http://vimeo.com/29001512

The wikipedia article contains a lot of detailed info on how well he did: http://en.wikipedia.org/wiki/Roger_Craig_%28Jeopardy!_contes...

The information is in the second video, I figured, why transcript Craig's description when he did a succinct job of it himself?

To be honest, there's little information other than what he divulged out there on the net, as it was a private tool. If I find more i'll write a followup, it's pretty fascinating.