Although the Structured Assessment of Violence Risk in Youth (SAVRY) and the Youth Level of Service/Case Management Inventory (YLS/CMI) are among the most widely used adolescent risk assessment tools, they conceptualize and measure strengths differently. As such, in this study, we compared the predictive validity of SAVRY Protective Total and YLS/CMI Strength Total, and tested conceptual models of how these measures operate (i.e., risk vs. protective effects, direct vs. buffering effects, causal models). Research assistants conducted 624 risk assessments with 156 youth on probation. They rated protective factors at baseline, and again at 3-, 6-, 9-, and 12-month follow-up periods. The SAVRY Protective Total and YLS/CMI Strength Total inversely predicted any charges in the subsequent 2 years (area under the curve scores = 0.61 and 0.60, respectively, p < .05). Furthermore, when adolescents’ protective total scores increased, their self-reported violence decreased, thus providing evidence that these factors might play a causally relevant role in reducing violence. However, protective factors did not provide incremental validity over risk factors. In addition, because these measures are brief and use a dichotomous rating system, they primarily captured deficits in protective factors (i.e., low scores). This suggests a need for more comprehensive measures.