Binary F1 Score (Phrase-span Bracketing) is a crucial evaluation metric for syntactic parsing tasks in the field of Natural Language Processing. Binary F1 evaluates only the correctness of bracket boundaries (phrase spans), ignoring labels, serving as a fundamental metric for constituency parsing. It is typically reported as a percentage or a score between 0 and 1. This metric is widely used in relevant benchmarks and papers, effectively reflecting model performance in this dimension. Higher values are better. It helps researchers and engineers quantify the actual performance differences of models in syntactic parsing scenarios, facilitating horizontal comparisons between different methods or model versions.