Probabilities given by the RFC for supernova spectra, with the data split into four time ranges after the explosion: 0–10 days, 10–20 days, 20–30 days, and 30–40 days. The classifier uses the pEW, FWHM, epoch, and type of each SN spectrum as input parameters, with 60% of the total sample used for training and the remaining 40% for testing. The red and blue bins correspond to SNe II and IIb, respectively.