In some cases, the significant chemical complexity encoded in certain existing atom types limits our ability to find these types via individual SMARTS patterns. This may in part be because of overly complex atom typing, which, in traditional force fields, needs to encode the chemistry required for all force field parameter types simultaneously. Switching to direct chemical perception may allow for much more straightforward parameter assignment. Our SMIRKY tool for working with direct chemical perception also had considerable success. SMIRKY generated SMIRKS patterns which capture more than 90% of the fragment types in smirnoff99Frosst for MiniDrugBank and 100% for AlkEthOH and PhEthOH. Coverage was less than perfect in part because there is a significant combinatorial problem in sampling chemical perception trees. This combinatorial problem is most pronounced in SMIRKY's results on torsions, where many atoms and bonds may require multiple decorators. The ability to automatically recover the chemical perception in these existing force fields is a promising first step toward sampling over chemical perception as part of force field parameterization.