This study offers a novel approach to evaluating the predictors of first-year grade point average (FYGPA) in college by using multiple imputation and dominance analysis to compare high school GPA (HSGPA), ACT® test score, and demographic factors. Unlike previous research that typically relied on single regression models, this study reveals more nuanced relationships between predictors. A key differentiator is the finding that neither HSGPA nor ACT Composite score consistently dominated across all models, challenging prior conclusions about their relative importance. The analysis also highlights the dominant predictive roles of English and math performance in high school. Additionally, this study confirms that academic achievement measures are far stronger predictors of FYGPA than demographic variables, with family income and gender being the least important. These findings are important because they provide a more nuanced understanding of the factors that predict college success, which can have significant implications for how students are admitted and how they are supported once enrolled. By demonstrating that high HSGPA and ACT scores are stronger predictors of FYGPA than demographic factors, the study reinforces the importance of academic readiness for student outcomes. Also, the emphasis on English and math performance as key predictors of success underscores the value of strong foundational skills, which can inform curriculum design and high school preparation programs.