Redshift evolution of the difference between the input model neutral fraction and best-fit neutral fraction. The MCMC analysis here considers our eight-parameter model for the EoR power spectra. Different thin grey curves stand for different reionization scenarios from GRIZZLY simulation. The black curve represents our fiducial GRIZZLY simulation while the blue and orange curves present C2RAY and 21CMFAST input scenarios. The best-fit parameter values are obtained using input power spectra at eight redshifts for each reionization scenario.