We were unable to achieve 100% accuracy on the GAFF labels. Fitting a SMARTS hierarchy to single molecules resulted in the best accuracy of 99.8%, but this result used a relatively large search space of 3 bits over a maximum graph depth of 3. When considering the smallest search space of 1 bit and 0 depth, the accuracy dropped to 83.0%. Interestingly, there was a jump in the accuracy at a depth of 2. This corresponds to chemical environments two atoms away, and based on the comments in the GAFF force field file (the main documentation of how GAFF types are defined) there are several types that are based on a graph depth of 2. Therefore, we see a correspondence between the depth considered in GAFF, and the accuracy improvement of the produced SMARTS hierarchy.