This article sets out to investigate the neglected role of academic gatekeeping in professional recruitment by studying 1,460 recommendation letters written by the eminent Columbia University sociologist Robert K. Merton (RKM). Partly solicited by academic selection committees and mostly out of enthusiasm for promising scholarship, RKM delivered thorough descriptions of about 560 different candidates with the intention of opening “gates” to academic appointments. In his evaluations of former students, RKM used mostly (merit-based) academic and personal criteria while also commenting on analytical skills or work ethic. In general, the skilled writer RKM developed in his letters a compelling prose style of affirmation that presented his protégés in the best of all lights, which partly explains his effectiveness as gate-opener. A systematic match of information from recommendations with all available CVs yields that the “success rate” of RKM’s efforts varies between 87 percent for promotions to professorship and 43 percent for external candidates applying for full professorships.