Distribution of the skeleton length of the fields for the different smoothings (in colours). The median of every run is computed for each field. The dashed lines correspond to the GRFs, and the crosses are for the 21cmFAST reionisation time fields. The black lines are the theoretical predictions. The shaded areas and the error bars represent the dispersion around the median (1st and 99th percentiles) of the GRFs and t_reion(r), respectively. The black dotted vertical lines represent the average of the predictions. Here, ν represents the value of the normalised reionisation times.