This paper investigates how state-space partitions affect data-driven approximations of transfer operators for chaotic systems. A modified bisecting K-means algorithm builds a hierarchy of regions while keeping the number of samples in each region more balanced. Tests on the Lorenz and Kuramoto-Sivashinsky systems track the convergence of stationary statistics, Koopman eigenfunctions, and temporal correlations as the partition is refined. The results reveal different convergence rates across the two systems and show that the irreversible part of the operator can better approximate some temporal correlations. Readers get a practical partitioning strategy and evidence for deciding whether additional states improve a statistical model enough to justify their cost.