Question: what kind of offense does bill belichick run

title: New England Patriots strategy
text: The Patriots run a modified `` Ron Erhardt - Ray Perkins '' offensive system installed by Charlie Weis under Bill Belichick . Both Ron Erhardt and Ray Perkins served as offensive assistant coaches under the defensive minded Chuck Fairbanks while he was head coach of the Patriots in the 1970s . This system is noted for its multiple formation and personnel grouping variations on a core number of base plays . Under this system , each formation and each play are separately numbered . Additional word descriptions further modify each play ( see below for examples ) . 

Answer: answer: The Patriots run a modified `` Ron Erhardt - Ray Perkins '' offensive system; this system is noted for its multiple formation and personnel grouping variations on a core number of base plays.