We’re in phase three of our machine-learning project now—that is, we’ve gotten past denial and anger, and we’re now sliding into bargaining and depression. I’ve been tasked with using Ars Technica’s trove of data from five years of headline tests, which pair two ideas against each other in an “A/B” test to let readers determine which one to use for an article. The goal is to try to build a machine-learning algorithm that can predict the success of any give