Spanish has a contrastive stress system with three major possibilities: antepenultimate, penultimate, and final stress. While penultimate and final stress are to some extent predictable, a major point of contention in the literature is whether antepenultimate stress assignment is rule-governed ( Harris 1983; Roca 1991; i.a.). By examining different analogical and grammatically-informed models and their predictive power in capturing experimental data, I show that a Maximum Entropy model ( Hayes & Wilson 2008) that includes syllable weight in its lexical representations is the best predictor of antepenultimate stress assignment. In doing so, I also dispute the claim that the trill in Spanish is a geminate tap ( Harris 1983), and provide support for its status as a singleton consonant.