x = % voluntary put $$ into pot, indicates a players preflop habit, how many flops do they take, how wide or tight ranges do they play

y = % preflop raise, how many hands does he raise before the flop

z = total aggression factor, calculated as times bet + times raised/ times called, indicates how aggressive villain plays postflop.

Stats are pulled out of pokersoftware tools like pokertracker, pokeroffice, holdem manager and others.