This limitation may be overcome by scoring the synthetic accessibility, i.e. by predicting how the molecule of a given structure is synthesizable. Previously, synthetic accessibility scores were based on single molecular properties selected manually by experts . With the emergence of ML and DL methods, new scores were designed. They can be divided into structure-based and reaction-based approaches. Structure-based approaches evaluate the feasibility of molecular structure, e.g. SAscore , SYBA , GASA . Reaction-based approaches predict the synthetic accessibility by capturing the similarity of synthetic routes deposited in reaction databases, e.g. SCScore , RAscore , CMPNN .