Predict figure skating world championship ranking from season performances (part 2: hybrid models learned by gradient descent)

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I recently posted the write-up on the first part of my project (Github repo) to predict how skaters would rank in the figure skating world championship from earlier scores that they earned in the season. The main idea is to separate the skater effect, the intrinsic ability of each skater, from the event effect, the influence of an event on a skater’s performance, so that a more accurate ranking could be built.