The document discusses revising the Topliss decision tree for analog synthesis based on 30 years of additional medicinal chemistry literature and data from the ChEMBL bioactivity database. It describes creating a "Matsy decision tree" directly from experimental matched molecular series data in ChEMBL, which supports most of the Topliss tree but suggests some differences. The authors developed a data-driven approach not limited to the original Topliss trees to make predictions backed by experimental evidence from targeted datasets.