You should mean beating Los Angeles, which means beating Los Angeles-beating Los Angeles. This is probably at 1980, the last game of the 76ers vs Celtics in the Eastern Conference finals. At home in Boston, Philadelphia leads Boston by a big margin, and Boston has no hope of entering the finals. Prior to this, the Celtics' arch-enemy Lakers had reached the finals. Seeing that there is no hope of winning the championship, Boston fans can't have a final confrontation with their old rivals. The audience shouted "Beat LA! ! "(Los Angeles for short), I hope Philadelphia will beat Los Angeles for itself in the finals. Since then, whenever Boston plays against the Lakers at home, fans will shout this slogan, and even fans of other teams will follow suit when their teams play against the Lakers at home, shouting, beat LA! !