Compactness parameter ξ_2.5of the core-collapse models in this study as a function of their initial helium star mass. The dotted line at ξ_2.5 = 0.35 separates most models that might explode (below the line) or implode (above the line). Orange points indicate models that are predicted to explode according to the explodability of the Ertl et al. (2016) and Müller et al. (2016) tests (using their ‘standard’ parameters), blue points are models that are predicted to explode according the Müller et al. (2016) test but not the Ertl et al. (2016) test, green points are models that is predicted to explode according to the Ertl et al. (2016) test but not the Müller et al. (2016) test, and grey points are models that would not successfully explode according to both tests.