This means that {HEAD ~ the first grid structure} preferably has {TAIL ~ more grid fields} than the second grid structure 
preferably has
This means that { HEAD ~ the first grid structure } preferably has { TAIL ~ more grid fields } than the second grid structure
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH