Although it is well established that Hertzian fracture characterizes stone knapping mechanics, its in-depth features on lithic products remain unclear. Observations on a basic component of the Hertzian fracture manifestation, the cone of percussion ‘system’, has previously considered to reveal knappers’ hand preference, yet offering contradictory predicting results within the context of blind tests conducted on experimental lithic products. In this study, basic features of the cone of percussion on stone flakes are re-approached in an effort to determine their exact relation to handedness manifestation during stone knapping. Experimental data analysis suggests that under certain circumstances stone knappers’ hand preference is strongly, but not absolutely, connected with the cone of percussion ‘system’ various geometrics. The pilot implementation of the suggested methodology on lithic artefacts produced by Neanderthals at Kalamakia cave-southern Greece, indicates that right-handers predominate among the flintknappers of the site.