Top row, left: Monte Carlo 1σ envelope on the estimated mass as a function of the true mass of the star. The black solid line shows the relative error 1σ envelope for the no mass loss sampling and reconstruction, the red line refers to the sampling from the grid with η = 0.4 and reconstruction on the grid with η = 0.0, while the green one to the sampling from η = 0.8 grid and reconstruction on the grid with η = 0.0. The dotted lines mark the medians. Right: as in the left panel, but as function of the RGB relative age of the stars. Bottom row: as in the top row, but for the age relative error.