Complex sentence: There have been several incidents since the 1970's bewteen the Yid Army and Cheslesa, one notorius battle took place in the 1972 season at White Heart lane, where Chelsea fans, is samll numbers entered sections of the Terraces that were mainly occupied by Spurs fans.
Split into simpler sentences: There have been several incidents since the 1970's between the Yid Army and Cheslesa. One notorius battle took place in the 1972 season at White Heart lane where Chelsea fans, in small numbers, entered sections of the Terraces that were mainly occupied by Spurs fans.