Beyond minutes played: Rotation architecture as a persistent club-level signature in elite basketball

Basketball substitutions are usually interpreted as tactical decisions, but repeated substitution sequences may also reveal stable team-level tendencies in how competitive exposure is organised. We reconstructed 65,657 on-court stints from two complete EuroLeague regular seasons and defined a proposed five-indicator team rotation signature (S5), evaluated over two seasons: structural exposure per minute, fragmentation, rotation irregularity, compressed recovery, and fourth-quarter SEI share. Game-level signatures were identifiable above chance, with leave-one-out nearest-centroid accuracies of 26.7% (95% CI [23.2, 30.0]) and 31.1% (95% CI [27.8, 34.5]) against chance levels of 5.6% and 5.0%, and noisy game-level profiles aggregated into reliable seasonal fingerprints. Across the 17 clubs present in both seasons, matched clubs remained closer to their own previous signature than to randomly paired club-season profiles (mean distance 1.68 vs. 2.62; p < .001). Game state affected rotation depth far more than the signature: a 20-point margin explained 14.33% of within-club variance in effective rotation but 0.80% in signature deviation. Structural consolidation was not detectably associated with winning. However, clubs concentrating structural exposure in the fourth quarter won fewer games (r = -0.38, 95% CI [-0.66, -0.05]); this exploratory association replicated in both seasons but attenuated after controlling for previous-season success and should not be read causally. Rotation architecture therefore behaves as a comparatively persistent club-level property rather than a by-product of in-game substitution decisions.