The Five-Year Inflection: Statistical Evidence for Sub-Period Structure in BaZi Luck Pillar (Dayun) Cycles

This pilot study tests the Split-Character Method, which proposes that each 10-year BaZi Luck Pillar (Dayun) comprises two functionally distinct 5-year sub-periods — the first dominated by the Heavenly Stem, the second by the Earthly Branch. Using biographical data from 16 public figures (912 year-records), we compared explanatory power (η²) of 10-year vs. 5-year grouping via ANOVA. Results show 5-year grouping explains significantly more variance (mean η² = 0.315 vs. 0.204; permutation test p < 0.0002). Supplementary data package includes 16 biographical timeline JSONs and computed Four Pillars/Luck Pillar sequences for all subjects.