Persuasiveness

BP and AP judges decide which team was most persuasive.

• Two elements: persuasiveness rests on plausible reasons showing an argument is true and important (analysis, or matter), and on the clarity and rhetorical power with which those reasons are conveyed (style, or manner). See Matter / Manner.
• They are not separate criteria. An argument is never persuasive merely because it was stylish; style is persuasive only insofar as it conveys analysis and its significance. Reasons the judge cannot understand cannot persuade.
• Plausibility: claims more intuitive to the OIV carry a lower burden of proof, but seriously implausible claims earn weak or no support.
• What does not count by itself: the number of arguments, how clever or interesting they were, or arguments the judge knows but the team did not make.
• Style: judges must not penalise accent or unfamiliar idioms. The only legitimate problem is if the judge genuinely cannot understand the speaker despite their best efforts.