Group work is valuable but is “riddled with social inequities”. Instructors often have well honed strategies for helping teams, but in large classes they are unable to even identify which teams are in trouble! We developed and piloted a tool that elicits feedback from students periodically, and depicts their responses visually such that even in huge numbers of teams, instructors can spot imperiled groups. Around a quarter of the teams observed had significant inequities, but only a small selection of them self identified as troubled, meaning we would not have found them without the tool.