This paper presents an analysis of how school mathematics credentials, particularly calculus, coupled with elite college degrees can allow for presumed proficiencies, resulting in acceptance to a selective alternative route program (SARP) for secondary mathematics. However, such credentials do not guarantee deep mathematics knowledge nor effective teaching, particularly in low-income schools serving a majority of Black and Latinx students. We present a portrait of two NYC Teaching Fellows secondary mathematics teachers, their mathematics preparation and credentials, and how their supervisors viewed them. We further present findings from two years of classroom observations and show that these SARP mathematics teachers resorted to the direct, procedural teaching style they had known themselves, held superficial mathematical understandings, regularly made math errors, and often struggled to coherently answer students' mathematical questions.