Discrepancy in the inferred initial masses between methods that probe the pre-SN core mass or luminosity of the progenitor vs. the ones that age-date its surrounding environment. Our results (2D probability density distribution in green) show the transformation of the simulated delay-time of the SN progenitor to M_ZAMS (x-axis), assuming a lifetime-mass relation for single stars (Fig. 1 of Z17). The y-axis is the transformation of the simulated M_He, preSN to M_ZAMS using the inverse of Eq. (1). The points are nearby Type II SNe with observed estimates of M_ZAMS with both groups of techniques, shown in Table 1.