Certainly, such games are not designed for adjustability of {HEAD ~ the relative importance} played by {TAIL ~ chance} and skill 
played by
Certainly , such games are not designed for adjustability of { HEAD ~ the relative importance } played by { TAIL ~ chance } and skill
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH