Since 1984, the National Research Foundation (NRF) in South Africa has evaluated and rated researchers, using peer review of the recent research outputs and impact of each applicant's work. This article reports on an investigation into the evolution of the research careers of Y-rated researchers (young researchers with potential) in the natural sciences and engineering from 1984-2005, the support they received, the obstacles they faced, and their opinion of the evaluation and rating system. Most respondents endorsed the system and the career-development opportunities of a Y rating. Half of the former Y-rated researchers remained in South African academia; only a quarter, however, expressed satisfaction with the levels of support received. The responses, as well as recommendations for further strategies to retain and develop promising young scholars, are of special interest to the NRF, university administrators, and policy authorities, since Y-rated researchers represent the next generation of South Africa's top researchers. (Contains 3 tables, 5 figures, and 1 note.)