Residuals of the VR interpolations in L_bol (upper panels), R (middle panels), and g (lower panels) as a function of the evolutionary age. The tracks were computed with a chemical composition described by Y = 0.25, [α/Fe] = 0.3, and [Fe/H] = 0.7 and correspond to masses of 0.8 M_⊙ (left panels) and 0.9 M_⊙ (right panels). The evolutionary ages shown cover the evolution of the star up until the base of the RGB. The TO age of the tracks is shown in each panel as a vertical dotted line.