for the tdc data sets. The correlation between these two similarity measures with the RF kernel is similar to that of the linear kernel. However, the linear kernel exhibits discontinuities because of the binary nature of circular fingerprints, leading to gaps in CKA linear . In addition, conclusions about the inner structure of the RFs can be drawn from CKA rf : If two RFs exhibit similar performance, then the forests they build are also similar. Consequently, optimizing the radius of circular fingerprints will unlikely lead to substantial improvements in performance because RFs trained on circular fingerprints of varying radii are aligned. A large benchmarking study of molecular fingerprints also found that circular fingerprints with different radii perform similarly for virtual screening. 4 Furthermore, our experiments show that even the internal structure of the RFs trained on fingerprints with different lengths is similar.