Fable 5.1 vs Argon: 100発言 debate, retractions steal the show

The experiment's structure matters as much as its finding. The author split the debate into 10 chapters, one per stage from premise to withdrawal, with roughly 10 statements per chapter and a rule that each reply must add a rebuttal or conditional amendment rather than plain agreement. That constraint pushed the models into the kind of back-and-forth that produced two-stage retractions, as in the final chapter where Fable 5.1 first withdrew a plan to halt new customers, then also withdrew the word 'decline' in favor of redirecting heavy steps to the nearest deadline.

The author is explicit that the comparison between the two models is not fair. The moderator's instructions were not equally detailed for both sides, and the moderator Twill is itself a Claude-family model like Fable 5.1, which the author suggests may have made Fable 5.1 look stronger. Argon also misread one of Fable 5.1's statements, at comment 72, and the moderator let the next turn fix it rather than stepping in.

Beyond the retractions, the author notes a stylistic quirk: Fable 5.1 tends to offer very precise figures, such as a claim that 20 of 30 companies finalize in the last two days, and the neatness of the numbers invites readers to believe them even when the model labels them guesses.