- Duolingo Chess has issues with 24% of puzzles in Section 7 being ineffective or borderline.
- Main problems include 'Theme Not Present' (puzzles not teaching labeled themes) and 'Branching Variations' (puzzles too hard for beginners).
- Other issues involve AI-generated puzzles, confusing hints, opaque payoffs, and bugs, affecting millions of daily users.
- The root cause is likely a shallow tagging system that misses puzzle narratives, leading to misclassification and poor difficulty calibration.
- A proposed fix is using an AI agent trained on human-tagged data to flag problematic puzzles for review, improving effectiveness without redesigning all puzzles.
- Despite flaws, Duolingo Chess is praised for its gamification and ability to engage beginners, with fixes seen as achievable due to systematic errors.