We expand the scope of the literature on willingness to compete by asking how it varies with academic ability and whether and how it predicts career choices at different ability levels. The literature so far has mainly focused on career choices made by students at the top of the ability distribution, particularly in academic institutions. We experimentally elicit the willingness to compete of 1500 Swiss lower-secondary school students at all ability levels and link it to the study choice that students make upon finishing compulsory school. Our analysis of the relationship between willingness to compete and the study choice considers the full set of study options, including the options in vocational education. We find that willingness to compete predicts which study option high-ability students choose, not only among academic specializations but also among vocational careers, and, importantly, it also predicts whether low-ability boys pursue upper-secondary education upon finishing compulsory schooling. Our second main contribution is to systematically explore how willingness to compete varies with academic ability. We find that high-ability boys, but not girls, are substantially more willing to compete compared to all other children. As a consequence, the gender gap in willingness to compete is significantly lower among low-ability students than among high-ability students. Overall, our study highlights that insights from the literature on willingness to compete are relevant for a broader set of policy questions, populations and choices.