Top: maximum kinematic twist measured between 1 and 8 R_e as a function of the stellar halo triaxiality T(8 R_e). FRs are shown in blue, SRs in red; both TNG50 and TNG100 samples are shown. The gray line and shaded band show the median of the twist distribution as a function of T(8 R_e) and the 25th and 75th percentiles. Even though the majority of the TNG galaxies have small kinematic twists, high T galaxies are more like to display a kinematic twist. Bottom: distribution of the maximum kinematic twist for the TNG50 and TNG100 samples (green step histogram) compared with the ePN.S sample (hatched histogram). The filled green histogram shows the distribution of the TNG galaxies after their mass function is matched to that of the ePN.S sample; the gray histogram is the mass-matched TNG distribution convolved with a measurement error and is consistent with the data.