Roughly 200 narrators of hadith in Sunni collections have been labeled as Shi'ites or associated with Shi'ism. Depending on where one draws the line, the list of “Sh'iites” among second/eighth century “Sunni” hadith scholars can read as a virtual “who’s who” of early Sunni hadith scholarship in Iraq. Ibn Qutayba counts figures as pivotal to the Sunni hadith tradition as Abu Ishaq al-Sabi'i, Shu'ba b. al-Hajjaj and Yahya b. Sa'id al-Qattan among their number. It is clear that the “Shi'ism” that such figures were associated with must have differed greatly from that of figures like Jabir al-Ju'fi and Abu al-Jarud, who played an equally pivotal role in the development of Shi'ite sectarian identities. In this paper, I engage in a statistical analysis of the biographical literature on these narrators with the aim of understanding the spectrum of Shi'ite sentiments that existed among these narrators and how it correlated with Sunni hadith scholars’ assessments of their reliability. My analysis is based on five factors. The first of these is the volume of references to the Shi'ism of a given narrator in the biographical literature. The second factor is the terminology used to describe Shi'ite narrators. This generally consists of the verb “yatashayya',” the label “Shi'i,” and a number of adjectives that attenuate or accentuate either of the latter. More explicitly negative labels were also applied, such as rafd, ghuluww and their derivatives or sectarian labels such as “al-khashabiyya.” The third factor is whether a given narrator was also included in Imami or Zaydi biographical dictionaries and how he was categorized therein. The fourth factor is the grade of reliability given to the narrator. The fifth and final factor is that of anecdotes that shed light on the sorts of attitudes and positions associated with these narrators’ Shi'ism. These generally consist of an excessive attachment to 'Ali and the family of the Prophet, criticism of other companions, or participation in or support for 'Alid revolts. While each of these factors is informative in isolation, the correlations between them allow for a sharper picture of the spectrum of meanings associated with Shi'ism in the Umayyad and early 'Abbasid eras and a detailed understanding of how they were regarded by Sunni scholars of hadith.