One anthem clip was collected per nation from 2026 World Cup matches - covering all 48 competing nations. The score measures how precisely supporters and players sang their national anthem in tune, and how consistently they sang throughout it. Six nations had a professional artist perform at their opening match rather than the supporters and players. Each of these was replaced with a rendition from a later match featuring supporters and players singing.

Each clip was trimmed to the sung portion only. Demucs - a professional-grade audio separation tool - isolated the vocal track from crowd noise, the stadium public address system, and the live band. Pitch was then extracted from the isolated vocals using the pyin algorithm, producing 43 pitch readings per second. Each reading was assigned a confidence score, so moments where the microphone panned away or the signal was weak were automatically down-weighted.

Pitch accuracy (40%) - the percentage of sung moments that land within one fifth of a semitone of a note fitting the supporters and players' own tuning. Nations singing slightly sharp or flat of standard concert pitch are not penalized.

Commitment (40%) - the fraction of the clip's duration carrying detected singing. Supporters and players who sing every word score higher than those who trail off or mumble.

Melodic richness (10%) - whether the singing contains genuine melodic movement. Both a monotone drone and random noise score zero; real melodic variety scores one.

Pitch stability (10%) - how steadily singers hold their notes between consecutive moments, rather than sliding or wavering off pitch.

Alongside the individual rankings, nations are grouped into four tiers based on their overall pitch performance. The tiers are an additional layer of context on top of the ranking - they indicate which nations are genuinely performing at a higher or lower level of pitch accuracy. Tier 1 nations are the most in-tune in the analysis, their scores clearly and consistently higher than those in lower tiers. Tier 2 nations perform above the midpoint of the field, Tier 3 below it, and Tier 4 contains the lowest-scoring nations. Within each tier, the individual ranking still holds.