Sorting by Best Match within Landing Page Settings
Best Match sorting option within Landing Page settings represents Best Match sorting option from Sorting&Pagination area within Hawk workbench (which is usually based on Score). Therefore, when Best Match is selected, Best Match sorting settings from Workbench-> Data Configuration-> Sorting&Pagination will be honored.
Sorting set from Sorting&Pagination area:
Sorting any options other than Best Match within Landing Page Settings
When any other sorting option listed under this drop-down menu is selected (e.g.: Sale Price) the Best Match sorting option for this landing page only will be swapped behind the scenes with sorting option based on your selection.