Distribution of the alignment between optical filaments connected to galaxy clusters and the major axis of each cluster as inferred from its X-ray emission. Fractions and 68% confidence intervals were computed in equal-sized angular bins, following the method described in Damsted et al. (2023). Different colors indicate different projected cluster–filament distances used to compute the projected filament inclination. The gray-dashed horizontal line represents the uniform distribution, while the black-dotted vertical line indicates an alignment threshold of less than 25 degrees.