Franchise · Loyalty
The players who gave a single franchise their entire encyclopedia-attributed career, ranked by seasons of service. The rarest thing in modern sports — a whole career, one crest. The mirror image: the journeymen who wore the most.
Longest single-club career
A one-club man is a player whose entire corpus-attributed career sits under a single franchise (careerKeys-resolved — the same attribution the team pages and entity search use). Tenure is the span the corpus records (first→last season); NFL skill rows are complete 1999+, legend-era grids validated. Minimum 8 seasons. Data: franchise-careers.json.