  One of the greatest challenges in quantum chromodynamics is understanding the
hadronization mechanism, which is also crucial for carrying out precision
physics with jet substructure. In this Letter, we combine recent advancements
in our understanding of the field theory-based nonperturbative structure of the
soft drop jet mass with precise perturbative calculations of its
multi-differential variants at next-to-next-to-leading logarithmic (NNLL)
accuracy. This enables a systematic study of its hadronization power
corrections in a completely model-independent way. We calibrate and test
hadronization models and their interplay with parton showers by comparing our
universality predictions with various event generators for quark and gluon
initiated jets in both lepton-lepton and hadron-hadron collisions. We find that
hadronization models perform better for quark jets relative to gluon jets. Our
results provide the necessary toolkit for precision studies with the soft drop
jet mass motivating future analyses using real world collider data. The
nontrivial constraints derived in our framework are useful for improving the
modeling of hadronization and its interface with parton showers in next
generation event generators.
