Uncertainty in the mapping between M_ZAMS and the relative final mass M/M_ZAMS due to wind mass loss. Each colored bar corresponds to a specific wind algorithm combination defined in Table 2. The pluses, crosses, and circles correspond to η = 1.0, 0.33, 0.1, respectively. We employ the vertical bars to emphasize the spread. The uncertainty in wind mass loss limits the predictive power of stellar evolution studies for the final mass of stars of given initial mass. Only models with M_ZAMS = 35 M_⊙ and wind efficiency η = 1 reach the WR stage (cf. Table 4 and Sect. 3.4). They are shown in the rightmost panel and we list the WR mass loss algorithm only for them. The maximum relative mass for the four algorithm combinations using the H WR mass loss algorithm in the rightmost panel are the results obtained using the corresponding hot and cool mass loss combination with η = 0.1 (not reaching the WR phase).