The present study aims at investigating whether events of socially shared metacognitive regulation (SSMR) differ from each other when comparing their characteristics. These differences are labelled "variations in SSMR". The study is conducted in a peer tutoring setting at university and includes video data (70 h of video recordings) on the regulation behaviour of thirty students who participated in a semester-long peer tutoring intervention that was directed at knowledge co-construction. In addition to studying variations in SSMR, the current study aims at examining whether individual students' engagement in variations in SSMR is related to their performance on a knowledge test taken immediately after the peer tutoring intervention. Latent class cluster models were run to explore the presence of variations in SSMR. The trigger for SSMR, the number of students actively involved in SSMR, the level of elaboration during SSMR, and the function of SSMR in the collaborative learning process were included in the model as input parameters. A four-cluster model was selected as the best fitting model that demonstrated statistical significance. The four identified variations of SSMR were labelled as 'interrogative SSMR', 'affirmative SSMR', 'interfering SSMR', and 'progressive SSMR'. Regression analyses revealed that not all variations in SSMR are equally important for predicting students' performance. Students' engagement in interrogative SSMR was significantly positively related to students' performance on the knowledge test, whereas their engagement in interfering SSMR was negatively related. In contrast, the frequency of students' involvement in affirmative SSMR or progressive SSMR demonstrated no significant relation with students' performance. By unravelling the multifaceted character of SSMR, the present study allows to extend and to refine the emerging theory on shared regulation.